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The crayfish described here was discovered while the author was carrying out an investigation on the biology of the crayfishes of central and southeastern Illinois.2 According to the collection data compiled during this investigation, this crayfish is limited in distribution to the southern part of Illinois and was not found in the collections which were made in the eastern and central parts of the state.

Of the previously known albinistic species of the genus Cambarus (C. ayersii, C. setosus, C. hamulatus, C. cryptodytes, and C. cahni) two are inhabitants of the Missouri Ozarks, and have been reported from several caves in the southwestern part of the state. While considerable confusion as to the status of C. ayers.ii and C. setosus still obtains, it is clear that the new species described below, although having affinities with them, is markedly distinct. The specimens on which this description is based were collected by Mr. Leslie Hubricht on July 4, 1941, and have been in my collection since early in 1942. Several efforts to obtain additional specimens have failed.

Recent students of the crayfishes are finding the conservative treatment given by Ortmann and Faxon to the species comprising the genus Cambarus less and less satisfactory in the light of increasing knowledge of the group. Ortmann and Faxon divided this genus into a number of subgenera, sections and groups, some of which, because of their distinctiveness, seem to deserve the status of higher categories. As long as Cambarus was small and the available information scanty, the conservative classification was not only logical but definitely practical. Now, with more accurate knowledge of specific ranges, and with the finding of many new species, new relationships have been discovered which are not adequately expressed by Ortmann's and Faxon's treatments. The splitting of the old genus Cambarus into two genera by Creaser (1933) has done little to relieve the congestion.

LITERATURE CITED BROCK, V. E. 1938 Notes on the ranges of fishes from Lower California and the west coast of Mexico; with a discussion on the use of diving apparatus in making collections. COPEIA, 1938(3): 128-131. CARR, A. F. JR., and LEWIS J. MARCHAND 1942 A new turtle from the Chipola River, Florida. Proc. New England Zool. Club, 20: 95-100, pl. 14-15. HOBBS, HORTON H. JR. 1942 A generic revision of the crayfishes of the subfamily Cambarinae (Decapoda, Astacidae) with the description of a new genus and species. Amer. Midland Nat., 28(2): 334-357, pl. 1-3.

One of the most interesting phases of the history of crayfish dispersal and modification is that associated with the origins of troglobites. There are a few generalizations which can be drawn concerning the distributions and the origins of the several stocks which have engendered populations that have been able to meet the demands of a subterranean existence. In order to gain the proper perspective of the distributional relationships of the cavernicolous crayfishes with their epigean relatives, a brief summary of the distributions of the four genera with hypogean representatives is presented. The largest genus in the family Astacidae, Procambarus, comprises more than 100 species and subspecies of which six are true troglobites. The range of the genus extends from Cuba, Guatemala and Honduras northward to Illinois and southern New England. Most of the species are found in the southeastern parts of the United States and Mexico where they are confined largely to the Coastal Plain and Piedmont Provinces. Only in Mexico have representatives been able to cross the divide into the Pacific drainage. The six albinistic species and subspecies are known only from Florida (4), Veracruz, Mexico (1), and Pinar del Rio, Cuba (1); that from the latter has not been described. The monotypic genus Troglocambarus is known only from caves in the Florida peninsula. The genus Orconectes, the second largest in the family, is composed of approximately 60 species and subspecies, and among them five troglobitic taxa have been recognized. The range of this genus is largely confined to the Mississippi and Great Lakes drainage systems, but a few species have reached the extreme southeastern part of the United States, and two occur east of the Appalachian system in an area extending from Maine to Virginia. The hypogean representatives are found in the Interior Low Plateaus of southern Indiana, central Kentucky and Tennessee, and northern Alabama. The genus Cambarus, comprising some 40 species and subspecies, is represented by six troglobitic species within the United States. Its range extends from the Gulf of Mexico (Texas to northern Florida) to Canada; however, most of the species occur in the eastern part of the United States, along the slopes of and in streams arising in the Appalachian Mountains. The present discussion concerns the cavernicoles of this genus.

This new species (type locality, Conchas Reservoir, San Miguel Co., New Mexico) is being named Orconectes causeyi in honor of Dr. David Causey. Description is based on holotype, morphotype, allotype, and 40 paratypes. Types and paratypes are deposited at U. S. National Museum and Tulane University. Additional known specimens are annotated. Origin, distribution, ecology, life history, and relationships are discussed briefly. The species is known from Arkansas, Rio Grande, and Colorado River drainages; spanning the Continental Divide. This new species is being named in honor of Dr. David Causey, Emeritus Professor of Zoology, University of Arkansas. I am especially indebted to Dr. Causey for training in ecology and invertebrate zoology and for countless instances of advice and encouragement. It is with pleasure that I name this new species for him as a small token of great esteem. The new species was first observed by the author when three specimens were collected in a gill net during a fishery investigation of Conchas Lake, New Mexico, on 15 January 1960. The specimens were sent to Dr. H. H. Hobbs, Jr., after the author was unable to identify the species. Dr. Hobbs duly advised that they represented a new species and offered his advice and assistance in preparation of a description. This paper is a result of these events. Orconectes causeyi, sp. nov. Holotype male, form I.-Body stocky, subovate, depressed; abdomen slightly shorter than cephalothorax (56.4-57.9 mm). Height of cephalothorax (Figs. 1 and 2) slightly less than width in region of caudodorsal margin of cervical groove (25.4-25.7 mm); greatest width of cephalothorax (28.7 mm) about one-half the distance between caudodorsal margin of cervical groove and posterior dorsal margin of cephalothorax. Areola (i.e., thoracic, portion of cephalothorax on middorsial line) open. Cephalic portion less than twice as long as areola (37.3-20.6 mm) length of areola 35.6%v of length of cephalothorax. Rostrum long, excavate; sides converging; set off by weak lateral spines. Acumen with 'apex slightly curved dorsally, slightly longer than one third length of remainder of rostrum (4.7-11.0 mm). Margins of rostrum raised, keeled along dorsolateral edges; dorsal surface with longitudinal line of setiferous punctations along each margin medial to keels. Postorbital ridges well-developed, grooved laterad, terminating cephalad in weak anteriorly projecting spines. Branchiostegal spines

The Propinquus Section is defined as follows: Gonopods of male extending cephalad to or beyond the coxopodite of third pereiopod; tips, separated for a relatively great distance, straight or only slightly curved except in 0. peruncus and 0. punctimanus, and in neither of these is the curve as great as in the members of the Virilis Section (Compare figs. 21, 22, and 23 with the pleopod of 0. virilis, fig. 16).

One of the characteristics of the genus Cambarellus is the very small size of all known species. Only a few other crayfishes, such as Procambarus youngi Hobbs and Orconectes clypeata (Hay) which are pygmies in their own genera, are as small as the larger members of Cambarellus. For this reason they are commonly either overlooked by collectors, or regarded as immature specimens and consequently ignored. This genus is poorly known throughout its range, and the extent of its wide distribution in the United States has not been realized. .

Cambarus buntingi, a new species of crayfish from the Cumberland Plateau and Great Valley in Tennessee and the Cumberland Plateau in Kentucky, is described. Color notes, relationships, distribution, life history notes and ecological data are given. The crayfish described herein represents one member of a species complex that Ortmann (1931) united under the name Cambarus montanus. Girard (1852) described C. montanus from "Within the Alleghany (sic) ranges in Virginia and Maryland: tributaries of James river in Rockbridge Co. (Va.): Shenandoah river in Clark Co. (Va.), and Cumberland (Md.) of the hydrographical basin of the Potomac; Sulphur Spring, Greenbrier river, an affluent of Kenhawa (sic) river (Va.) [W. Va.] of the Ohio basin." Unfortunately, the planned subsequent full description and illustrations of Girard's new species were never given, and the original brief account was inadequate to permit the recognition of C. montanus with certainty. Hagen (1870) treated C. montanus as a synonym of C. bartonii (-Astacus bartonii, Fabricius, 1798) after examining one of the type specimens. The syntypes of C. montanus were destroyed by the Chicago fire of 1871 while on loan to William Stimpson (Faxon, 1914). Faxon (1885) supported Hagen's opinion but later (1914), after noting that "Cambarus bartonii from the Alleghany region of West Virginia and Virginia ... fall into two, sets of forms," gave C. montanus subspecific ranking under C. bartonii. The insight of Hagen (1870) and Faxon (1885, TABLE 1-.Measurements (mm) of Cambarus (Puncticambarus) buntingi Holotype Allotype Morphotype Carapace Height 20.4 15.4 17.1 Width 25.6 21.6 22.3 Postorbital carapace length 41.2 35.1 35.4 Total length of carapace 49.8 43.3 44.1 Rostrum Width 5.8 4.6 4.5 Length 8.6 8.2 8.7 Areola Width 3.1 3.6 3.3 Length 18.0 14.8 15.0 Chela Length, palm 14.6 9.6 10.6 Width, palm 19.5 13.7 15.8 Length, lateral margin 49.6 33.1 35.7 Length, dactyl 31.1 20.9 22.5

Discovery of Cambarellus texanus, from the Gulf coastal plain of southeastern Texas, helps clarify relationships within the genus. New distributional records for the three species previously known from Texas include 15 new county records. Two females of the species described below have been in the collections at Tulane University (TU P-649) since 1941, but they were conjecturally identified as Cambarellus puer. Penn and Hobbs (Texas J. Sci. 10: 452-483, 1958) listed an erroneous locality for C. puer based on these specimens, collected in Matagorda County, 4 mi S of Bay City. The new species was first recognized as such by the junior author, who collected it in Jackson and Matagorda Counties in 1966. Adequate material for study was not obtained until 1972, when the senior author found it in two additional counties. Discovery of this crawfish, a relative of Cambarellus ninae and an associate of C. puer over part of its range, helps define the relationship between the latter two species, which formerly was held in question (Hobbs, Proc. Biol. Soc. Washington 63: 89-96, 1950). Reports on the distribution of Cambarellus in Texas have been few (Hobbs, Amer. Midl. Nat. 34: 466-474, 1945; Hobbs, 1950; Penn and Hobbs, 1958). The localities reported here, based on collections made by the authors, constitute major extensions of the known ranges of the three species previously recorded from Texas. Cambarellus texanus new species Cambarellus puer.-Penn and Hobbs, 1958, p. 475, fig. 67 (in part).

A study of the crayfishes of the Ozark Mountains region of Arkansas, Missouri and Oklahoma has brought six new species and subspecies of these animals to my attention. These crayfishes all belong to the genus Orconectes, one of six genera comprising the subfamily Cambarinae (Decapoda: Astacidae). In the locality records listed below numbers prefixed by the word "Lot" refer to numbers in the collection of the University of Kansas Museum of Natural History. Numbers prefixed by the letter "M" refer to catalogued lots in the University of Michigan Museum of Zoology.

A more accurate method of measuring the carapace is proposed. The use of the posterior margin of the epistome as a possible taxonomic structure is introduced. The subgenus Jugicambarus is emended. Cambarus crinipes, a new species of crayfish from the Cum- berland Plateau in Tennessee, is described. Color notes, relationships, distribution, life history notes and ecological data are given. In crayfish systematics the length of the carapace has been tradi- tionally measured from the tip of the rostrum to the midcaudodorsal margin of the carapace ("total length of carapace"). Damaged rostrums, coupled with the intrinsic variability of the structure, sug- gested that a more consistent measurement of the length of the carapace would be one currently utilized in the suborder Natantia and several sections of the suborder Reptantia: the distance from the angle of the orbit to the midcaudodorsal margin of the carapace (carapace length). Computations using this measurement usually attenuate range values. Narrower ranges of variation hopefully will make data more useful in comparing specimens. The term carapace length is so similar to total length of carapace that to avoid confusion it is here proposed to designate the measurement from the angle of the orbit as postorbital carapace length. Besides possible taxonomic merit, postorbital carapace length has a manual benefit. In measuring, calipers tend to slip off the tip of the acumen. Also, specimens in late premolt stages or early postmolt are so pliable that the rostrum and caudal margin of the carapace bend. The reinforced suborbital angle maintains itself so that only concentration on the caudal margin of the carapace need be maintained. By subtracting postorbital carapace length from total length of carapace, a more stable rostrum length is attained, thus removing the problem of deciphering the cephalic extremities of the postorbital ridges. During recent studies of existing problems with certain crayfish groups, a structure not previously mentioned, and only occasionally illustrated, has proven to be of considerable importance. Since the group in which use of this structure has shown some merit occupies a large geographic range still under study, it is introduced here so that other researchers may become aware of its potential taxonomic value. This structure, here designated the epistomal zygoma (Fig. lj), is the thickened posterior margin of the epistome lying immediately anterior to the mouth. Hobbs (1969), in his proposals of subgeneric groupings for the genus Cambarus, erected the subgenus Jugicambarus, which encom- 103

This is the second of a series of four papers on the crawfishes of Louisiana; the first, on the genus Cambarellus, appeared in this journal (Penn, 1950b), wlhich see for introductory reimiarks. Many of the specimens on which these studies are based liave since bcen placed in other collections. Abbreviations for these ale as follows: AMNH = American Museum of Natural History, ANS Academy of Natural Sciences of Philadelphia, HHH Horton H. Hobbs, Jr. personal collectioi, INHS = Illinois Natural History Survey, LSU = Louisiana State University, MCZ Museum of Comparative Zoology at Harvard University, TU -Tulane University (Department of Zoology), UMMZ = University of Michigan Museum of Zoology, and USNM United States National Museum.

This is the third of a series of four papers on the crawfishes of Louisiana. The first two, on the genera Cambarellus and Orconectes respectively (Penn, 1950, 1952), should be referred to for the introductory remarks and a key to the abbreviations denoting disposition of the specimens. To the latter add: CM-ICarnegie Museum, Pittsburgh, Pa., and ASMNH=Alabama State Museum of Natural History, Tuscaloosa, Ala.; and delete UMMZ (University of Michigan, Museum of Zoology) of which the entire crustacean collections have been transferred to the U,SNM. A number of habitat factors (e.g., depth of water, flow, shaded vs. exposed, etc.) are routinely recorded by the writer for each collection made. However, other collectors who have given crawfish to the Tulane collection have not always recorded data on the same factors. Hence, in summarizing habitat data for each species the number of lots (=collections) analyzed is in each case represented by somewhat less thian complete data.