Cuatro Ciénegas Work by Dad
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CRUSTACEA FROM THE BOLSÓN OF CUATRO CIÉNEGAS,
GERALD A. COLE
Route 4, Box 892
Flagstaff, Arizona 86001
Twelve crustaceans are known from the Cuatro
Ciénegas basin. These include: the cirolanid
isopods Speocirolanathermydronis, Sphaerolana
interstitialis, Sphaerolana affinis; one
stenasellid isopod Mexistenasellus
Coahuila,the first of the Stenasellidae found
in the New World; and two endemic hadzioid
(weckeliid) amphipods originallyassigned to
Mexiweckelia, M. colei, and M. particeps. M.
particeps will be referred to the monotypic
new genusParamexiweckelia (Holsinger, in
press). These six species were described from
the basin and are endemic to it; thegenera
Sphaerolana and Paramexiweckelia have no
representatives outside the basin. Other
crustaceans include: aspecies of the brine
shrimp, Artemia; another anostracan, probably
a species of Streptocephalus; an
harpacticoidcopepod similar to Cletocamptus
albuquerquensis; an ostracod referable to
Chlamydotheca; an amphipod much likeHyalella
azteca, although designated here simply
Hyalella; and the decapod Palaemonetes
suttkusi. The lastspecies, Chlamydotheca, and
H. azteca were described originally from
Mexican material. Although crustaceandiversity
is low in its thermal waters, discovery of
more species can be expected in the Cuatro
Doce crustáceos son conocidos de la cuenca de
Cuatro Ciénegas . Estos incluyen: los isópodos
Sphaerolana interstitialis, Sphaerolana
affinis; un isópodo
estenasellidoMexistenasellus Coahuila, el
primer Stenasellidae descubierto en el Nuevo
Mundo; y dos anfípodos hadziidos(weckeliid)
endémicos originalmente asignados a
Mexiweckelia, M. colei y M. particeps. Se
referirá a M. particepscomo un nuevo género
monotípico, Paramexiweckelia (Holsinger, en
prensa). Dichas seis especies fueron
descritasde la cuenca donde son endémicas; los
géneros Sphaerolana y Paramexiweckelia no
tienen representantes afuera dela cuenca.
Otros crustáceos son: una especie de brine
shrimp, Artemia; un anóstraco probablemente
una especie deStreptocephalus; un copépodo
harpacticoide parecido a Cletocamptus
albuquerquensis; un ostrácodo referable
aChlamydotheca; un anfípodo parecido a
Hyalella azteca, y designado aqui Hyalella; y
el decápodo Palaemonetessuttkusi.
Chlamydotheca y las dos ultimas especies
fueron descritas originalmente de muestras
mexicanas. Aunque ladiversidad de crustáceos
sea baja en las aguas termales de la cuenca de
Cuatro Ciénegas , se espera el descubrimiento
demas especies locales.
INTRODUCTION.-The history of crustacean
studies in Cuatro Ciénegas is largely a saga
of serendipity, and lucky"firsts" in what soon
became a series of advances in Mexican
zoology. Many people contributed their energy
andpersonal talents to the field work, W. L.
Minckley being the most avid collector of us
all. From the beginning, Dr.Thomas E. Bowman,
Division of Crustacea at the Smithsonian
Institution, sustained and guided us. His
counsel wasinvaluable, and on two occasions he
was the perfect host while I was in Washington
examining specimens and literaturehoused in
the U. S. National Museum. Furthermore, he was
kind enough to read this manuscript and to
criticize itconstructively. Other people to
whom I am indebted for pertinent information
are Drs. Denton Belk, John R. Holsingerand
It is the purpose of this paper to tell how
and where various new species were found and
to detail what happenedthereafter. The paper
will deal with: three new species of cirolanid
isopods and one new genus; one new genus
andspecies of the stenasellid isopods; and two
new species of hadziid amphipods belonging to
two new genera. All thespecies and two genera
are endemic to the Cuatro Ciénegas basin, and
four genera were described originally from
CuatroCiénegas material. The status of Mexican
carcinology in relation to Cuatro Ciénegas
will be discussed, and someprophesies about
future discoveries will be ventured.
Throughout, there may be a more anecdotal
style than is usual inmodem scientific
CRUSTACEAN DIVERSITY IN CUATRO CIÉNEGAS. The
impression, perhaps fostered by those who have
studiedthe organisms of Cuatro Ciénegas, is
one of exciting diversity. This does not apply
to the Crustacea, although there isanother
side to the coin that will be discussed
subsequently. The striking endemism and
abundance of new taxa, and theoccurrence of
several cirolanid isopods, a group that is
poorly represented in non-marine settings, may
have contributedto the notion of high
Actually, the number of crustaceans from the
valley of Cuatro Ciénegas is not impressive;
only 12 species have beennoted. The Amphipoda
and Isopoda of the Peracarida are fairly
abundant, but other major groups are poorly
represented.To date, no mysidacean
peracaridans have been found, although at
least four troglobitic species are known from
Among the Branchiopoda, a population of the
brineshrimp genus Artemia Leach 1819, was
sampled 20 March 1973 inLaguna Salada by
Denton Belk. Also, some immature anostracans
have been collected at various times from
ephemeralroadside pools; they are probably
some species of Streptocephalus Baird 1852. No
representatives of the Cladocera,however, have
been reported from the basin. The Copepoda are
represented by an harpacticoid close to, if
notconspecific with, Cletocamptus
albuquerquensis (Herrick) 1895.1/ Among the
other "entomostracans", some speciesof the
ostracod Chlamydotheca Saussure 1858 is
abundant, serving as a food item for the
endemic box turtle,Terrapene coahuila Schmidt
and Owens 1944. At least five species of
Chlamydotheca have been noted from Méxicoto
Amphipods referable to Hyalella Smith 1874,
designated H. azteca (Saussure) 1858 in many
papers concerned withCuatro Ciénegas fauna,
are ubiquitous. Palaemonetes suttkusi Smalley
1964, a decapod glass or grass shrimp,
occursin some lagunas in the basin.
Chlamydotheca, Hyalella azteca and
Palaemonetes suttkusi were described
initiallyfrom Mexican specimens (Saussure
1858; Smalley 1964). The endemic crustaceans
that were described later amount tosix
species. Thus 75% of the Cuatro Ciénegas
Crustacea have Mexican affinities, and 50% are
The reason for the low crustacean diversity in
the thermal and hypogean waters of Cuatro
Ciénegas may be rooted in theextreme stability
of such habitats. Recently, Ward and Stanford
(1983) discussed animal diversity in lotic
environments.In two instructive plots (their
Fig. 1 , p. 349, and Fig. 2, p. 351) the
authors showed highest diversity in
communitiessubjected to intermediate levels of
disturbing incidents. Lowest diversities occur
in thermal springs where constancyprevails,
and at the opposite end of the spectrum in
extremely disturbed habitats such as those
subjected to frequent acidmine discharges or
to heavy organic loading.
The thermal, interstitial, and subterranean
waters of Cuatro Ciénegas are stable habitats
that may account for(in additionto low
diversity) the presence of cirolanid and
stenasellid isopods as well as hadziid
amphipods. Flabelliferan isopods(including
some parasitic families as well as the
free-living Cirolanidae and Sphaeromatidae),
the Stenasellidae, andamphipods of the family
Hadziidae have not been successful in
colonizing the common types of epigean
freshwaterenvironments. The same can be said
for the mysidacean Peracarida, abundant in the
seas, but largely troglobitic orhalophilic
when inland. Mysis relicta Lovén 1861,
occurring in the deeps of northern
oligotrophic lakes, may be anexception to
this. The asellid isopods and gammarid
amphipods, by contrast, have invaded lakes,
springs, and streamsfar from the sea and have,
in some instances, moved directly from epigean
freshwaters into caves.
Bowman (1981) concluded that flabelliferan
isopods have been excluded from what we
consider normal epigeanfreshwater habitats by
the competition of aquatic insects, especially
the predaceous species, and their naiads,
nymphs,and larvae. Insects occur but rarely in
caves and hot springs, the inland habitats
where the non-parasitic flabelliferans
arefound. In the Cuatro Ciénegas basin one
small, cold-water laguna contains many benthic
mayfly naiads, but noflabelliferan isopods,
nor stenasellid isopods, nor hadziid amphipods
as far as is known.
Ward and Stanford (1982) discussed the
importance of temperature in the ecologic
evolution of insects, pointing out thatthe
original home of aquatic insects was in the
cool headwaters of streams. From there they
moved downstream andspread to warmer waters.
Very few species, however, invaded and
prospered in thermal waters. Shuster
(1981)remarked on the absence of predaceous
insects in a hot spring in Socorro, New
México, where a population offlabelliferan
isopods (Sphaeromatidae in this instance)
thrives. He attributed this, however, to
intense predation by theomnivorous isopod,
Thermosphaeroma thermophilum (Richardson)
After stating that the diversity of
crustaceans in the Cuatro Ciénegas
environments is low, it is time to point out
that itmight be much higher than we suspect.
First, the difficulty in collecting some of
the species leads to the conclusion thatthere
are more microhabitats and new species
awaiting discovery. The work of Dickson et al.
(1979) implies thathypogean crustaceans have
normal levels of genetic variability,
comparable to that of epigean forms.
Isolatingmechanisms, then, could lead to
speciation in the various interstitial,
subterranean, and thermal habitats of the
CuatroCiénegas basin. Second, as Frey (1982)
emphasized, the notion of cosmopolitanism in
the cladoceran Crustacea blindedworkers to the
host of undescribed species around us in North
and South America. This probably applies to
thecyclopoid copepods and ostracods also.
Diligent searching at shallow margins of
lagunas, pozos, and in aquatic weedbeds might
uncover the presence of some Cladocera,
Copepoda, and Ostracoda even though they have
not been taken inplankton collections from the
bolsón. Careful scrutiny, involving modem
techniques, or even old-fashioned methodsbased
on morphology, could well reveal many new and
perhaps endemic species.
Another point to consider hinges on the
abundance of weckeliid amphipods in various
waters of Cuatro Ciénegas(Holsinger and
Minckley 1971). Recently, Stock (1982)
presented statistical evidence that hadziid
amphipods andcyclopoids are mutually exclusive
in West Indies habitats. Validating this
generality on the basis of the
weckeliidmembers of the Hadziidae would make a
worthwhile research project in the basin. The
important factor in the relationshipseems to
be the predatory nature of the amphipods.
Moreover, Stock found the thermosbaenacean
crustaceans andhadziids rarely co-occur, yet
the former and cyclopoids are associated in a
normal fashion in West Indies groundwaters.At
this time only one thermosbaenacean species is
known from the mainland of North America; this
is Monodellatexana Maguire 1965, from the
Edwards Plateau, Texas. Suitable hypogean
habitats that lack weckeliid amphipodsmight be
the best places to find cyclopoid copepods
and, possibly, crustaceans closely related to
Monodella in theCuatro Ciénegas valley.
Several accounts of the various habitats in
the Cuatro Ciénegas basin have noted the
ubiquity of Hyalella azteca(Minckley 1969;
Cole and Minckley 1970, 1972; Holsinger and
Minckley 1971). In the years since those
reports at leasttwo new species of Hyalella
have been described in the American Southwest.
These are H. texana Stevenson andPeden (1973)
and H. montezuma Cole and Watkins (1977). The
idea of one species, H. azteca, ranging from
SouthAmerica to the treeline in North America
is on the wane, and it is not accurate to
assign a specific name to the
Coahuilahyalellids as has been done. The color
variation among different populations in the
waters of Cuatro Ciénegas is striking,and one
unique population, especially, comes to mind:
one spring contains snow-white individuals
with black eyes.Probably there are many
species masquerading as Hyalella azteca and
some of these may be in the bolsón of
The concept of cosmopolitanism has
oversimplified the taxonomy of Artemia.
Therefore, it is unrealistic to
designateanimals from North America as A.
salina (Linnaeus) 1758, described originally
from Lymington, Southhampton,England. Clark
and Bowen (1976) recommended that the term A.
salina be dropped for the brine shrimps (found
on sixcontinents), except for, perhaps, the
type locality. Their paper marked the starting
point for a more realistic examinationof brine
shrimp populations, and presented evidence for
far more heterogeneity than had been suspected
previously. TheArtemia from Laguna Salada has
yet to acquire a specific name.
Other species of the Anostraca can be
anticipated in the Cuatro Ciénegas basin.
Streptocephalus linden Moore 1966,S. machine
Moore 1966, Thamnocephalus mexicanus Linder
1941, and T. platyurus Packard 1879 have
beenreported from Coahuila, although not from
Cuatro Ciénegas (see Belk 1975). Five other
species of Streptocephalushave been reported
from Texas, or Mexican states bordering
Coahuila. There are, therefore, many
possibilities as towhat the ultimate taxonomic
designation will be when applied to the
immature forms from Cuatro Ciénegas.
It is not illogical to assume that more faunal
surprises await us as more subterranean
habitats are investigated in theCuatro
Ciénegas bolsón. The African shrimp genus,
Potamalpheops, is represented in North America
by a singleMexican species, the troglobitic,
white, eyeless P. stygicola (Hobbs 1983). This
relict decapod recalls the formerconnection of
the present African and American continents
and leads to predicting that careful searching
or serendipitousgood fortune will add to the
unique faunal list of Cuatro Ciénegas .
ISOPODA, FLABELLIFERA.-Cirolanidae. The first
crustacean described as a new species from the
Cuatro Ciénegasbasin was the cirolanid isopod,
Speocirolana thermydronis Cole and Minckley
(1966). At that time the genusSpeocirolana was
represented by two other species, both
Mexican. Bolívar (1950) reported an isopod
from a San LuisPotosí cave, assigning it to
the marine genus Cirolana Leach 1818, but
placing it in a new subgenus, Speocirolana,and
giving it the specific name pelazei. Three
years later, Rioja (1953) described a new
form, Cirolana(Speocirolana) bolivari,
collected in a Tamaulipas cave. Bowman (1964)
raised Bolívar's subgeneric nameSpeocirolana
to full generic rank. Thus, S. thermydronis
became the third certain species of the genus.
It is probablethat Conilera stygia, described
by Packard (1900) on the basis of animals
collected in springs near Monterey, NuevoLeón,
is another species of Speocirolana, although
it has not been found since Packard's report
and, apparently, notypes were deposited (T. E.
Bowman, pers. comm.). Certainly it is not a
member of the marine genus Conilera Leach1818,
to which it was assigned by Packard.
The animals referable to Speocirolana are much
like typical marine cirolanids except for
their eyeless condition and lackof
pigmentation. They have five obvious pleonites
(abdominal segments) anterior to the
pleotelson, although the lateralmargins of the
fourth and fifth are reduced, and the genus
represents the third of nine types of pleonal
segmentation inorder of increased fusion of
pleonites (Bowman 1975a, Fig. 4). Its category
shows it slightly more modified thanCirolana
and Conilera, both of which show only a slight
reduction of the fifth pleonite; they belong
to Bowman'ssecond type. The exopod and endopod
are well developed on each uropod, forming a
typical crustacean biramousappendage. A major
character of the genus is that the first three
pairs of pereopods are prehensile, followed
byambulatory appendages 4-7. Packard's
Conilera stygia also has subchelate,
prehensile pereopods 1-3, if we are to relyon
his words of 1900, "Only the first three pairs
of legs are short, with a very thick hand; the
four hinder pairs are longand slender."
With the published description of Speocirolana
thermydronis, only four genera of cirolanid
isopods were known fromthe mainland of North
and Middle America. These included:
Cirolanides texensis Benedict 1896 from caves
of theEdwards Plateau of Texas; three species
of Speocirolana, (perhaps four if Conilera
stygia can be assigned to thatgenus);
Creaseriella anops (Creaser) 1936 from the
Yucatán Peninsula; and Antrolana lira Bowman
1964 from aVirginian cave. All are troglobitic
forms. Nine years later another blind,
unpigmented cirolanid, Mexilana saluposiBowman
(1975a), was named from a San Luis Potosí
cave, raising the total genera to five.
In 1982 Contreras-Balderas and Purata-Velarde
published an account of another species,
Speocirolana guerrai. Thedescription of the
new species was based on a study of 48
specimens from a small cave near Linares,
Nuevo León. In thesame journal, in the paper
directly following the description of S.
guerrai, the fifth and sixth species of
Speocirolanawere named S. pubens and S. endeca
from San Luis Potosí and Tamaulipas,
respectively (Bowman 1982a)..Speocirolana
endeca earned its name by being the llth
species of troglobitic Mexican cirolanid to be
described (seeBowman 1982a, p. 23).
Bowman's two species of Speocirolana nicely
fit the distributional pattern formed by the
first four species andConilera stygia
(Contreras-Balderas and Purata-Velarde 1982,
Figs. 28-32). The geographic alignment, from
S.pelazei and S. pubens in San Luis Potosí to
the most northern species, S. thermydronis,
closely follows the UpperJurassic coastline
according to Burckhardt (1930) and Imlay
(1943). With reference to the boundaries of
marineembayments in México proposed by Axelrod
(1979), the Speocirolana species are found
near the old Paleocene andEocene shorelines. A
pre-Tertiary origin for the genus seems
reasonable. The isopods probably moved
directly fromretreating seas into interstitial
and hypogean habitats without an intermediate
epigean freshwater stage. The location
ofPackard's "Conilera " within the north-south
line formed by the Speocirolana species
prompted Contreras-Balderasand Purata-Velarde
(1982, p. 10) to write " . . . se reafirma la
suposcion de que 'Conilera' stygia Packard
debiorepresentar una Speocirolana
Speocirolana thermydronis was described on the
basis of one 15-mm female collected in April,
1964, by Mary L.Allesio, a member of a
University of Colorado Museum field group. The
specimen was sent to us by Clarence J.McCoy.
Twenty-nine more animals were collected in
August, 1967, and additional distributional
and descriptive dataresulted from that
(Minckley and Cole 1968a). We were
apprehensive about describing a new species
from a study ofonly one specimen, but the
earlier descriptions of S. pelazei and S.
bolivari were so detailed that we were certain
thatthe Cuatro Ciénegas isopod was different.
We were not the first in the annals of
hypogean carcinology to describe a newtaxon
from such scanty material; two more instances
will be mentioned in later pages.
Many European and North American zoologists
have invaded México to investigate the
nation's unique crustacean fauna.It is,
therefore, worthy of mention and indeed a
happy thought that 50% of the species of
Speocirolana (if we excludeConilera stygia)
were described by Mexican scientists!
The discovery of the new genus Sphaerolana
Cole and Minckley (1970) was owed to William
S. Brown. Brown, thena graduate student at
Arizona State University, was studying the box
turtle Terrapene coahuila. Stomach contents
ofsome preserved Terrapene specimens in Tempe
contained remains of isopods, which Brown
asked me to examine. Theisopods were in very
poor condition, but obviously were unique. I
though they might belong to the flabelliferan
familySphaeromatidae, because many were rolled
tightly in a sphere. Brown detailed the
location of the pozo from which theturtles had
been collected (immediately christened Pozo
Tortuga by Cole and Minckley) and the next
summer, August1967, we began searching for
isopods in the same pool. A few were found
when travertine blocks were broken apart,but
the results were generally disappointing.
Later we discovered the best way to collect
the white, eyeless isopods wasto pull up
emergent vegetation at pool margins and
examine the muddy roots; the crustaceans were
abundant there. Soonwe had adequate study
material and we sent specimens to Dr. Bowman
at the Smithsonian Institution. He observed
thatthe mouthparts were typical of a cirolanid
isopod rather than a sphaeromatid, and that
the isopod could not be referred toany known
genus. The two family names were combined to
create the new generic name for the isopod,
SphaerolanaCole and Minckley 1970. Since then
no isopods referable to Sphaerolana have been
discovered outside the CuatroCiénegas basin.
Although two other blind, white cirolanids are
capable of rolling into a sphere, they are
fundamentally different fromSphaerolana. These
are Creaseriella Rioja 1953 from the Yucatán
Peninsula and Faucheria Dollfus and Viré
1905from caves in France. Creaseriella
resembles Speocirolana in having five
well-developed pleonites anterior to
thepleotelson, the last two having indistinct
lateral margins in both genera. Sphaerolana
has but two abdominal segmentscephalad to its
pleotelson, and the caudal one has indistinct,
covered lateral margins. Faucheria reveals
four pleoniteswith well-developed lateral
margins, but the transverse sutures are
incomplete, representing nearly fused
segments. It isthe last type in Bowman's
(1975a, Fig. 4) nine categories arranged in
order of increasing fusion of
pleonites.Sphaerolana characterizes the eighth
The uropodal rami of Creaseriella are strong,
with large endopods and exopods. Those of
Sphaerolana are scarcelyrepresented and are
inserted in a lateral notch near the end of
the protopod. In Faucheria the uropodites are
representedby subterminal, reduced structures
on the protopod. The uropods of Sphaerolana
have evolved further from the typicalcirolanid
type. All the pereopods of the Yucatán
Creaseriella are ambulatory; the first three
pairs are subchelate andprehensile in
Faucheria and Sphaerolana, as they are in
members of Speocirolana. There seems to be no
closerelationship among the three
sphere-forming genera. Probably the ability to
roll has developed independently in
Our early specimens of Sphaerolana (S.
interstitialis) came from habitats clustered
near the northern tip of the
Sierra de San Marcos (see Minckley 1969, Fig.
2; Cole and Minckley 1970, Fig. 40; Holsinger
and Minckley 1971, Fig.4). The most remote
site was 6 km south of the tip near the
eastern slope. Serendipity played a role in
the discovery ofW. affinis in a pozo 12 km
southeast of the nearest known S.
interstitialis. The pit was carpeted with
Chara exceptfor the central, deepest portion,
where water entered; there, clearly visible,
were clean, white pebbles. The
funnel-shapedpit stirred our imaginations to
such an extent that we named it Funnel Poso
[sic], Pozo Embudo being beyond ourcollective
linguistic talent. Dwight W. Taylor, always on
the alert for new mollusc habitats, asked
George L. Batchelderto dive down carrying a
small sieve and to bring back a sample of the
pebbles and, perhaps, associated gastropods.
Atthat time, August 1967, Batchelder was a
graduate student and he complied. To our
surprise, the sieve contents includedsome
eyeless, white isopods that we immediately
recognized as belonging to Sphaerolana. We
assumed they wereconspecific with those taken
earlier near the tip of Sierra de San Marcos.
Later, when it was possible to dissect
andexamine them microscopically, several
differences emerged, and the small
funnel-shaped pozo, about 2 km northeast
ofEjido Santa Tecla and about 20 km southeast
of the town of Cuatro Ciénegas, became the
type-locality for Sphaerolanaaffinis Cole and
Minckley 1970. A pattern began to emerge at
about that time: the fauna of the eastern part
of the basin,and especially the "southeastern
lobe", is different from that of the western
Sphaerolana affinis differs from S.
interstitialis in details of antenna 2,
pleopod 1, pleotelson, and the uropod. Ofthese
the most interesting is a small bilobed
structure, representing the exopod and endopod
of the typical isopod uropod.The two lobes,
situated in a shallow pit on the
posterolateral border of the protopod, extend
slightly beyond the protopodsurface. S.
interstitialis is further modified from the
typical cirolanid; its uropodites are reduced
even more; they arerepresented by only a
minute marginal mound within the
posterolateral pit. The mound bears two or
three setae. Onlythese setae reach and extend
past the protopod margin.
At the northern tip of Sierra de San Marcos is
a small spring and pool that we christened
Taylor's Spring, for reasonsnow forgotten. The
small spring is shown as a half-darkened
circle in Cole and Minckley (1970, Fig. 40)
and as an opencircle in Holsinger and Minckley
(1971, Fig. 4). A wide-mouthed quart jar was
placed in the spring, its open end
tippedupward at an angle of about 350 toward
the hole from which the subterranean water
entered. Isopods that emergedduring the night
were trapped in the jar, although we suspect
that many individuals of Speocirolana were
able to swimto their freedom. Members of
Sphaerolana were unable to crawl up the glassy
slope, and most mornings we collectedanimals
that had emerged under the cover of darkness.
The Sphaerolana individuals were easily
separable into two types:one was typically S.
interstitialis; the other, on the basis of
antenna 2, pleopod 1, pleotelson, and uropod,
fitted thedescription of S. affinis. The
latter were 1.6-2.4 X the length of any
collected in the southeast-lobe habitats,
where theyoccurred alone, and were much larger
than the co-occurring S. interstitialis in
Taylor's Spring. Furthermore, theywere clumsy,
elongate, and unable to roll tightly to form a
Because the two species were indistinguishable
by the unaided eye when sample specimens from
allopatric populationswere examined, and
readily separable where they coexisted in
Taylor's Spring, the notion of character
displacement cameto mind immediately. Only
eleven years had passed since Brown and
Wilson's important paper (1956) entitled
"CharacterDisplacement" and meanwhile workers
had been confirming the exaggerated
differences between sympatric species
whencompared with the same characters in
allopatric situations. Now, 16 years after the
discovery of two kinds ofSphaerolana in
Taylor's Spring, an alternative explanation
seems reasonable. There could be three species
ofSphaerolana in the Cuatro Ciénegas basin.
There might be complete reproductive isolation
between the typical S.affinis in Funnel Pozo
and the elongate, awkward form in Taylor's
Spring. Possibly Speocirolana endeca
(Bowman1982a) from Tamaulipas should have been
Sphaeromatidae. At this time no sphaeromatid
isopods have been found in Cuatro Ciénegas
waters, and so only thecirolanids of the
Flabellifera are of concern to us here. It
should be mentioned, however, that five
species ofThermosphaeroma Cole and Bane 19782/
are found in hot springs of Chihuahua, Texas,
and New México. At present,the known species
of Thermosphaeroma occur in a north-south line
that corresponds closely to the western
boundaryof the Maastrichtian (Upper
Cretaceous) embayment (see Bowman 1981, Fig.
11) according to Axelrod (1979).
Thesesphaeromatid sites are all west of Cuatro
Ciénegas. Furthermore, they lie west of all
the known species ofSpeocirolana, the Mexican
stenasellid isopods, and the New World hadziid
amphipods, all forms which have relativesin
Cuatro Ciénegas. Some thermal bodies of water
in the basin, however, seem to be ideal
habitats forThermosphaeroma. Possibly a
sphaeromatid population will be discovered
there some day.
ISOPODA, ASELLOTA-Stenasellidae. When the
original description of Mexistenasellus
coahuila was published(Cole and Minckley
1972), we had collected only 10 specimens. The
first animals emerged from a small chunk
oftravertine that Minckley pulled from the
wall of the Laguna Juan Santos. Five specimens
in that small travertine blockwere all that
were collected in the summer of 1967 despite
an intensive search in the laguna and
throughout the CuatroCiénegas basin. The
following year four more specimens were taken
singly from four different habitats, and in 19
70 asingle individual was collected. In each
incident the isopod was taken more or less by
accident. They were found from 25cm to 3 m
below the water surface in soft organic
sediment, spongy travertine, and detritus
composed of fibrous plantfragments. The waters
that yielded these small isopods were
definitely warm; their temperatures were all
greater than300C, the hottest site being
Laguna Escobeda at 34.20.
Although we never learned how or where to
collect the stenasellids in Cuatro Ciénegas
waters, we know now, thanks toMagniez's (1978)
summary of our knowledge of stenasellids, that
we were not unique. The French Stenasellus
vireiDollfus 1897 was collected in 1896, but
despite minutely detailed searching through
ensuing years, it was notrediscovered until
1902! Perhaps the stenasellid habit of
constructing complex networks of tunnels in
compact claysediments, and occupying other
intricate interstitial galleries accounts for
the difficulty in collecting them.
Parenthetically,Adrian Dollfus described
Stenasellus virei on the basis of only one
individual collected in 1896!
The manuscript describing Mexistenasellus
coahuila was submitted first to a journal that
was having problems. It wasneglected for about
two years before we withdrew it and submitted
it to the Proceedings of the Biological
Society ofWashington, where it was accepted
and published in 1972. Later in the same year
two more species ofMexistenasellus were
described from San Luis Potosí, M. parzefalli
and M. wilkensi (Magniez 1972). Weappreciate
Magniez's courtesy in delaying his paper until
our publication appeared; he was aware of our
find and the longperiod our manuscript had
lain without attention. Two years later Argano
(1974) published the new M. magniezi
fromVeracruz, and later erected the new genus
Etlastenasellus to describe E. mixtecus from
Oaxaca (Argano 1977).Bowman (1982b) described
Mexistenasellus colei from a cave in
Tamaulipas, M. nulemex from Nuevo León
andEtlastenasellus confinis, the second member
of that genus from Oaxaca. Thus, there are
eight named stenasellidisopods known from the
New World, all from México. Certainly they are
more widespread. Since 1976, three
specimenshave been collected from deep wells
at San Antonio, Texas. They represent an
undescribed species (Glenn Longley, inlitt.,
11 July 1983). San Antonio is very near the
Eocene shoreline shown by Bowman (1981, Fig.
11, from Axelrod1979), where M. nulemex, M.
colei, parzefalli and M. wilkensi occur. M.
magniezi is farther south on theboundary of
the Paleocene marine embayment. The Cuatro
Ciénegas location of M. coahuila is west of
the Paleoceneboundary, and the two species of
Etlastenasellus are south of M. magniezi
between the Upper Cretaceous andPaleocene
Guy J. Magniez has continued working on the
stenasellids and summarizing our knowledge of
them. His studies of thewest African species
led him to conclude that the New World
Mexistenasellus species are closely related to
them,especially Parastenasellus (Magniez
1981). The splitting of Gondwana explains
this, implying ancient origins of
thestenasellids and suggesting that unknown
forms close to Mexistenasellus are awaiting
discovery, especially along thenortheastern
coast of South America from northern Venezuela
to the easternmost tip of Brazil (see Magniez
In February 1972, when the description of
Mexistenasellus was published, about 25
stenasellids were known fromEurope, Asia and
Africa. Now, throughout the world, extending
as far cast as the island of Borneo, more than
40 speciesin at least eight genera are known.
Eight species and two genera occur in México
alone, and maybe Glenn Longley'sTexas wells
will add another species at least.
Perhaps Mexistenasellus coahuila is the most
typical hypogean animal of all that have been
found in the thermalwaters of Cuatro Ciénegas.
From a study of subterranean animals in the
springs of northwestern Yugoslavia and from
asurvey of data in the literature, Sket and
Velkovrh (1981) concluded that stenasellid
isopods are the most characteristicgroup of
thermophilous hypogean animals, occupying
thermal waters even in tropical regions.
Moreover, Magniez(1978) used the stenasellids
to answer some general questions concerning
the biogeography, ecology, and physiology
ofcavernicolous animals found today in
temperate regions. At any rate, our find of
small red isopods in the travertine blockfrom
Laguna Juan Santos may have been the most
significant discovery among the Crustacea of
Cuatro Ciénegas: thefirst record of the
Stenasellidae from the New World.
Asellidae in México. The newly collected
specimens of what later proved to be
Mexistenasellus coahuila werepuzzling.
Although they were obviously asellotes (rather
than flabelliferans), we were aware of only
one other in theinland waters of México, the
so-called Asellus puebla Cole and Minckley
(1968) from epigean waters in the states
ofPuebla and México. Each Cuatro Ciénegas
asellote had two well-developed pleonites
anterior to the pleotelson, aprimitive
character when compared with the common
asellids of the United States and Canada,
Lirceus and Asellus;most of the latter are now
referable to Caecidotea Packard 1871. The red,
eyeless asellotes that emerged from
thetravertine in Laguna Juan Santos had never
been seen in the New World. We were not
prepared for them!
It seems opportune at this time to follow up
the story of Asellus puebla because it
pertains to Mexican, if not CuatroCiénegas
carcinology. Now we believe that Asellus
puebla is Caecidotea communes (Say) 1818,
described fromstreams around Philadelphia,
Pennsylvania, and the first of the inland
Asellota to be described in North America.
Say'sdescription of his Asellus communes
(1818, pp. 427-428) was inadequate in light of
modem work, causing muchconfusion for the next
century and a half. This began to clear up
when Williams (1970) examined specimens
collectednear Say's original sites in
tributaries of the Schuylkill River near
Philadelphia. Williams' excellent
redescription revealedthat Cole and Minckley
(1968) had busily described a form known for
150 years. How it was introduced to
Méxicoremains a problem. It was collected
about 101 latitude
farther south than had been reported for any
other member of the genus or closely related
genera at that time. Since then,however, other
asellids referable to Caecidotea have been
described from Veracruz (Argano 1972), Chiapas
(Bowman1975b), and other southern Mexican and
Guatemalan localities (Argano 1977). Suddenly
at least five asellids wereknown to occur far
south of "Asellus puebla ".
The etymologic history of the North American
generic names in the Asellidae was outlined by
Bowman (1975b). Briefly,Asellus Geoffroy St.
Hillaire 1764, an Old World genus, is
different, although at least one Alaskan
isopod may belongto it. Caecidotea was coined
by Packard (I 8 7 1), who believed that a
blind, white isopod from Mammoth
Cave,Kentucky, belonged to the marine family
Idoteidae. The first portion of Packard's
genus is from the Latin caecus,meaning blind.
Bowman (1975b) distinguished the first
American Asellus of Say (1818) from the Old
World genus.This left us with Caecidotea, on
the basis of priority, as the genus for many
of the asellid species this side of
theAtlantic. Unfortunately, many Caecidotea
species are pigmented epigean forms with
well-developed eyes. Others arewhite and
eyeless like the Mammoth Cave species, C.
stygia, that Packard described on the basis of
a single, damaged,immature specimen!
AMPHIPODA.-The first specimen of what proved
to represent a new genus of amphipod
crustacean, MexiweckeliaHolsinger and Minckley
(1971) was found in Taylor's Spring, shown as
a circle in Holsinger and Minckley (1971,
Fig.4) and a half-darkened circle in Cole and
Minckley (1970, Fig. 40). One morning in
August 1968, while I was showingDwight W.
Taylor the glass-jar trap used to catch
nocturnally emerging Sphaerolana and
Speocirolana, he called myattention to a
ghostly amphipod trapped on the surface film
of the tiny spring pool. The pool turned out
to be thetype-locality for Mexiweckelia
particeps Holsinger (in Holsinger and Minckley
1971), where it coexisted with thesmaller (ca.
3 mm, rather than 5.5 mm) and more widespread
M. colei, known also only from the Cuatro
Ciénegasbasin. The serendipitous observation
by Taylor led us to a method of collecting
these new amphipods, that we believedwere only
one species: we vigorously stirred the fibrous
plant detritus that lay at the bottom of some
small spring-poolsand pits, and searched for
animals trapped on the water surface. We
returned to Tempe at the end of August with
morethan 40 specimens of the tiny eyeless
crustaceans. The aid of Dr. John R. Holsinger
was sought in further study of theamphipods,
for he had published many papers on
subterranean peracaridans, and especially on
The amphipods from Taylor's Spring are related
to a group of genera that were considered, at
the time of their discovery,to be members of
the family Gammaridae. That meant that they
were the second freshwater gammarids to be
reportedfrom México, and they were the second
type of subterranean amphipod known from that
Villalobos-Figueroa 1961 had been described 10
years earlier from a cave in Tabasco. Since
then thefamily Bogidiellidae has been
redefined (Bousfield 1977) and is no longer
considered synonymous with
Gammaridae;Holsinger and Longley (1980)
assigned Mexiweckelia and related genera to
the family Hadziidae. Now the weckeliidgenera
are distinguished from other members of the
Hadziidae on the basis of differences in
uropod 3, the lower lip and,to a lesser
extent, the female pereopod 2 (gnathopod 2)
(Barnard and Barnard 1983). The Cuatro
Ciénegas animalsbelong to the weckeliid group.
The freshwater gammarid nearest to México may
be some member of the Gammaruspecos complex,
perhaps G. hyalelloides Cole 1976.
Meanwhile, in the dozen years that have passed
since the description of the two Mexiweckelia
species at least ninemore species of
subterranean amphipods have been named from
México, and three or four undescribed forms
have beennoted (Holsinger 1982). Most of these
are bogidiellids from southern México (Ruffo
and Vigna Taglianti 1977), butMexiweckelia
mitchelli was described by Holsinger (1973)
from material collected in a Durango cave.
Furthermore,two new hadziids (weckeliid group)
have been found in the cenotes of Yucatán,
Campeche and the Territory of QuintanaRoo, and
assigned to a new genus, Mayaweckelia
Holsinger (1977). Taxonomic changes have added
further to thecomplexity of the Mexican
After the description of the two Mexiweckelia
species from Cuatro Ciénegas there were
discoveries which suggestedthe genus was
rather widespread. Holsinger (1973) described
Mexiweckelia texensis from an artesian well in
SanMarcos, Texas, in the same paper that
reported M. mitchelli. With further study he
decided that the Texas speciesrepresented a
new genus, Texiweckelia, and the original
species of 1973 was found to be comprised of
two species ofTexiweckelia, T. texensis and T.
insolita, plus a new genus and species
Alloweckelia hirsuta. A third species
ofTexiweckelia, T. samacos, was also present
in the San Marcos well (Holsinger and Longley
1980). The remarkablecongeneric coexistence of
three Texiweckelia species lost its meaning
when Barnard and Karaman (1982) erected thenew
genus Texiweckeliopsis on the basis of T.
insolita, and changed T. samacos to
Holsingerius samacos, gen.nov. These changes
left Mexiweckelia restricted to the Cuatro
Ciénegas bolsón and Cueva de la Siquita in
Durango.The Durango species still belongs to
Mexiweckelia (Holsinger, in litt. July 1983),
diminishing the endemism ofCuatro Ciénegas to
the level it was when Holsinger and Minckley
(1971) reported the discovery of two species
of a new,supposedly endemic genus
Mexiweckelia. This will be offset when M.
particeps becomes Paramexiweckeliaparticeps, a
new monotypic genus, known only from Taylor's
Spring (Holsinger, in press). We often
wondered whichspecies, M. colei or M.
particeps, Dr. Taylor spotted on the surface
film that day in August 1968; now we can
ask,"Which genus did he see?"
All the freshwater hadziids are troglobites or
phreatobites; they are found in Eurasia, in
North America around theCaribbean, and are
associated with the Tethys shores. The
bogidiellids are much more widespread, and the
discovery ofa new species in the East Indian
Stock (1983) fulfilled his belief in the
antiquity of the family, it having reached a
nearly world-wide distribution beforethe break
up of Pangaea. Bousfield (1982) suggests that
the Hadziidae and Bogidiellidae are about the
same age andfairly young, going back to the
Middle Cretaceous. Whatever the case, at least
two bogidiellids have been discovered inSan
Marcos, Texas (Holsinger and Longley 1980,
Barnard and Barnard 1983) and the gap between
Texas and southernMéxico may be closed some
day with bogidiellids, as it is today with
species of the weckeliid group of the
ARGANO, R. 1972. An asellid of the
subterranean waters of Veracruz, México
(Crustacea, Isopoda). QuaderniAccademia
Nazionale dei Lincei, Problemi Attuali di
Scienza e di Cultura 171:35-42.
. 1974. Mexistenasellus magniezi, n. sp., a
blind aquatic isopod from Veracruz, México
(Crustacea). QuaderniAccademia Nazionale dei
Lincei, Problemi Attuali di Scienza c di
-. 1977. Asellota del Messico meridional e
Guatemala (Crustacea, Isopoda). Quaderni
Accademia Nazionale dei Lincei,Problemi
Attuali di Scienza c di Cultura 171:101-124.
AXELROD, D. 1. 1979. Age and origin of Sonoran
desert vegetation. Occ. Pap Calif. Acad. Sci.
BARNARD, J. L. and C. M. BARNARD. 1983.
Freshwater Amphipoda of the World: I.
Evolutionary Patterns. II.Handbook and
Bibliography. Hayfield Assoc., Mount Vernon,
VA. i-xix, 1-830.
, and G. S. KARAMAN. 1982. Classificatory
revisions in gammaridean Amphipoda
(Crustacea), Part 2. Proc. Biol.Soc. Wash.
BELK, D. 1975. Key to the Anostraca (Fairy
Shrimps) of North America. Southwest. Nat.
BOLIVAR y PIELTAIN, C. 1950. Estudio de una
Cirolana cavernicola nueva de la region de
ValIes, San Luis Potosí,México. Ciencia,
BOUSFIELD, E. L. 1977. A new look at the
systematics of gammaroidean amphipods of the
world. Crustaceana(suppl.) 4:282-316.
. 1982. Amphipoda (Palaeohistory). In Yearbook
of Science and Technology, pp. 96-100. McGraw
Hill Book Co.,New York.
BOWMAN, T. E. 1964. Antrolana lira, a new
genus and species of troglobitic isopod from
Madison Cave, Virginia.Intemat. J. Speleol.
. 1975a. A new genus and species of
troglobitic cirolanid isopod from San Luis
Potosí. Occ. Pap. Mus. Tex. Tech Univ.27:1-7.
. 1975b. Three new troglobitic asellids from
western North America (Crustacea: Isopoda.-
Asellidae). Intemat.j. Speleol.7:339-356.
. 1981. Thermosphaeroma milleri and T. smithi,
new sphaeromatid isopod crustaceans from hot
springs inChihuahua, México, with a review of
the genus. J. Crust. Biol. 1:105-122.
. 1982a. Speocirolana pubens and S. endeca,
new troglobitic isopods from México
(Flabellifera: Cirolanidae). Assoc.Mexican
Cave Stud., Bull. 8:1323/Bull. Tex. Mem. Mus.,
. 1982b. Three new stenasellid isopods from
México (Crustacea: Asellota). Assoc. Mexican
Cave Stud., Bull.8:25-38/Bull. Tex. Mem. Mus.
. 1982c. Mysidacea. In S. H. Hurlbert and A.
Villalobos-Figueroa, Editors. Aquatic Biota of
México, Central Americaand the West Indies,
pp. 201-202. San Diego St. Univ., San Diego.
BROWN, W. L., JR. and E. 0. WILSON. 1956.
Character displacement. Syst. Zool. 5:49-64.
BURCKHARDT, C. 1930. Étude synthétique sur le
Mésozoique mexicain. Mémoires de la Société
CLARK, L. S. and S. T. BOWEN. 1976. The
genetics of Artemia salina. J. Hered.
COLE, G. A. and W. L. MINCKLEY. 1966.
Speocirolana thermydronis, a new species of
cirolanid isopodcrustacean from central
Coahuila, México. Tulane Stud. Zool. 13:17-22.
.. 1968. A new species of aquatic isopod
crustacean (Genus Asellus) from the Puebla
Plateau, central México. Proc.Biol. Soc. Wash.
. 1970. Sphaerolana, a new genus of cirolanid
isopod from northern México, with description
of two new species.Southwest. Nat. 15:71-8 1.
. 1972. Stenasellid isopod crustaceans in the
western hemispheres new genus and species from
México-with a review ofother North American
freshwater isopod genera. Proc. Biol. Soc.
. and R. L. WATKINS. 1977. Hyalella montezuma,
a new species (Crustacea: Amphipoda) from
Montezuma Well,Arizona. Hydrobiologia
CONTRERAS-BALDERAS, S. and D. C.
PURATAVELARDE. 1982. Speocirolana guerrai sp.
nov., cirolanidotroglobio anoptalmo de la
Cueva de la Chorrera, Linares, Nuevo León,
México (Crustacea: Isopoda). Assoc.
MexicanCave Stud., Bull. 8:1-12/Bull. Tex.
Mem. Mus. 28:1-12.
DICKSON, G. W., J. C. PATTON, J. R. HOLSINGER
and J. C. AVISE. 1979. Genetic variation in
cave-dwellingand deep-sea organisms, with
emphasis on Crangonyx antennatus (Crustacea:
Amphipoda) in Virginia. Brimleyana2:119-130.
FREY, D.G. 1982. Questions concerning
cosmopolitanism in Cladocera. Arch.
HOBBS, H. H., JR. 1983. The African shrimp
genus Potamalpheops in México (Decapoda,
HOLSINGER, J.R. 1973. Two new species of the
subterranean amphipod genus Mexiweckelia
(Gammaridae) fromMéxico and Texas, with notes
on the origin and distribution of the genus.
Assoc. Mexican Cave Stud., Bull. 5:1-12.
. 1977. A new genus and two new species of
subterranean amphipod crustaceans (Gammaridae
s. lat.) from the YucatánPeninsula in México.
Assoc. Mexican Cave Stud., Bull. 6:15-25.
. 1982. Amphipoda. In S. H. Hurlbert and A.
Villalobos-Figueroa, Editors, Aquatic Biota of
México, Central Americaand the West Indies,
pp. 209-214. San Diego St. Univ., San Diego.
. In press. Paramexiweckelia, a new genus of
subterranean amphipod crustacean (Hadziidae)
from northern México.Intemat. J. Speleol.
, and G. LONGLEY. 1980. The subterranean
amphipod crustacean fauna of an artesian well
in Texas. SmithsonianContrib. Zool. 308:i-iv,
1-62. - . and W. L. MINCKLEY. 1971. A new
genus and two new species of
subterraneanamphipod crustaceans (Gammaridae)
from northern México. Proc. Biol. Soc. Wash.
IMLAY, R. W. 1943. Jurassic formations of the
Gulf region. Bull. Amer. Assoc. Petrol. Geol.
27:1407-1533.MAGNIEZ, G. 1972. Deux
Stenasellidae cavemicoles nouveaux de
l'Amérique centrale: Mexistenasellus
parzefalli,n. sp. et Mexistenasellus wilkensi
n. sp. (Crustacea Isopoda Asellota). Intemat.
J. Speleol. 4:19-31.
. 1978. Quelques problemes biogeographiques,
écologiques et biologiques de la vie
souterraine. Bull. Scientifique deBourgogne
1981. Biogeographical and paleobiogeographical
problems in stenasellids (Crustacea Isopoda
Asellota of undergroundwaters). Internat. J.
MINCKLEY, W. L. 1969. Environments of the
bolsón of Cuatro Ciénegas, Coahuila, México
with special reference tothe aquatic biota.
Tex. West. Press, Sci. Ser. 2:1-65. Univ. Tex.
El Paso, El Paso.
and G. A. COLE. 1968a. Speocirolana
thermydronis (Crustacea:Isopoda) from
northeast México, re-discovery [sic],habitat,
and supplemental description. Tulane Stud.
Zool. Bot. 15:2-4.
. 1968b. Preliminary limnologic information on
waters of the Cuatro Ciénegas basin, Coahuila,
México. Southwest.Nat. 13:421-431.
PACKARD, A. S., JR. 1871. On the crustaceans
and insects. In A. S. Packard, Jr. and F. W.
Putnam, Editors. TheMammoth Cave and its
inhabitants, pp. 739-761. Amer. Nat. 5(12).
. 1900. A new eyeless crustacean from México.
Proc. Amer. Assoc. Advan. Sci. 49:228.
RIOJA, E. 1953. Estudios carcinologicos. XXX.
Observaciones sobre los cirolánidos
cavernícolas de México(Crustáceos, Isópodos).
Anales del Instituto de Biologia Mexicana,
Universidad Nacional Autónoma de
RUFFO, S. and A. VIGNA TAGLIANTI. 1977.
Secondo contribute alla conoscenze del genere
Bogidiella in Messicoe Guatemala (Crustacea,
Amphipoda, Gammaridae). Quaderni Accademia
Nazionale dei Lincei, Problemi Attuali
diScienza e di Cultura 171:125-172.
SAUSSURE, H. 1858. Mémoire sur divers
crustacés nouveaux des Antilles et du Mexique.
Mémoires de la Société dePhysique et
d'Histoire Naturelle de Geneve 14:417-496.
SAY, T. 1818. An account of the Crustacea of
the United States. J. Acad. Nat. Sci. Phila.
SHUSTER, S. M. 1981. Life history
characteristics of Thermosphaeroma
thermophilum, the Socorro
isopod(Crustacea:Peracarida). Biol. Bull.
SKET, B. and F. VELKOVRH. 1981. Podzemeljske
zivali v termalnih vodah (Subterranean animals
in thermal waters).Bioloski Vestnik 29:91-119.
SMALLEY, A.E. 1964. A new Palaemonetes from
México. Crustaceana 6:229-232.
STEVENSON, M. M. and A. E. PEDEN. 1973.
Description and ecology of Hyalella texana n.
sp. (Crustacea:Amphipoda) from the Edwards
Plateau of Texas. Amer. Midl. Nat. 89:426-436.
STOCK, J. H. 1982. The influence of hadziid
Amphipoda on the occurrence and distribution
of the Thermosbaenaceaand cyclopoid Copepoda
in the West Indies. Polskie Archiwum
. 1983. Discovery of a bogidiellid amphipod
crustacean in inland waters of the East Indian
sarawacensis n. sp. Crustaceana 44:198-204.
WARD, J. V. and J. A. STANFORD. 1982. Thermal
responses in the evolutionary ecology of
aquatic insects. Ann.Rev. Ent. 29:97-117.
. 1983. The intermediate-disturbance
hypothesis: an explanation for biotic
diversity patterns in lotic ecosystems. In T.
D.Fontaine, III, and S. M. Bartell, Editors.
Dynamics of lotic ecosystems, pp. 347-356. Ann
Arbor Sci. Publ., AnnArbor.
WILLIAMS, W. D. 1970. A revision of North
American epigean species of Asellus
(Crustacea: Isopoda). SmithsonianContrib.
Table 1.-- Crustacea Known from the Bolsón of
Cuatro Ciénegas, Coahuila, México.
Artemia Leach 1819
Streptocephalus Baird 1852
Cletocamptus albuquerquensis (Herrick) 1895
Chlamydotheca Saussure 1858
Speocirolana thermydronis Cole and Minckley
Sphaerolana interstitialis Cole and Minckley
Sphaerolana affinis Cole and Minckley 1970
Mexistenasellus coahuila Cole and Minckley
Hyalella Smith 1874
Mexiweckelia particeps (Holsinger) in
Holsinger and Minckley (1971),
Holsinger in press
Palaemonetes suttkusi Smalley 1964
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