I /OH HARVARD UNIVERSITY LIBRARY OF THE Museum of Comparative Zoology /^^ c. /^Fl'Al,.^ ^> O i: L t,:^ //o 1 VOLUME 5 1957 lULANE UNIVERSITY NEW ORLEANS TULANE STUDIES IN ZOOLOGY is devoted primarily to the zoology of the waters and adjacent land areas of the Gulf of Mexico and the Caribbean Sea. Each number is issued separately and con- tains an individual study. As volumes are completed, title pages and tables of contents are distributed to institutions exchanging the entire series. Manuscripts submitted for publication are evaluated by the editor and by an editorial committee selected for each paper. Contributors need not be members of the Tulane University faculty. MEMBERS OF THE EDITORIAL COMMITTEES FOR PAPERS PUBLISHED IN THIS VOLUME Jose Alvarez del Villar, Escuela Nacional de Ciencias Biologicas, Mexico Reeve M. Bailey, University of Michigan Dorothy E. Bliss, American Museum of Natural History Donald J. Borror, Ohio State University Thomas E. Bowman, United States National Museum Frank A. Brown, Jr., Northwestern University Fenner A. Chace, Jr., United States National Museum Elisabeth Deichmann, Harvard University Arnold B. Grobman, Florida State Museum Cadet H. Hand, Jr., University of California Edward S. Hathaway, Tulane University Joel W. Hedgpeth, College of the Pacific Horton H. Hobbs, Jr., University of Virginia Arthur G. Humes, Boston University Ernest A. Lachner, United States National Museum Ernst Mayr, Harvard University Robert R. Miller, University of Michigan B. Elwood Montgomery, Purdue University George S. Myers, Stanford University M. Graham Netting, Carnegie Museum Thurlow C. Nelson, Rutgers University George Henry Penn, Tulane University David M. Pratt, University of Rhode Island Ralph I. Smith, University of California Grover C. Stephens, University of Minnesota Royal D. Suttkus, Tulane University Edward H. Taylor, University of Kansas Milton B. Trautman, Ohio State University H. Marguerite Webb, Goucher College Minter J. Westfall, Jr., University of Florida Austin B. Williams, University of North Carolina Verner J. Wulff, Syracuse University CONTENTS OF VOLUME 5 NUMBER PAGE 1. GAMBUSIA HETEROCHIR, A NEW POECILIID FISH FROM TEXAS, WITH AN ACCOUNT OF ITS HYBRID- IZATION WITH G. AFFINIS Clark Hubbs 1 2. NEW CALANOID COPEPODS OF PONTELLA DANA AND LABIDOCERA LUBBOCK WITH NOTES ON THE DISTRIBUTION OF THE GENERA IN THE GULF OF MEXICO Abraham Fleminger 17 3. THREE NEW CRAYFISHES FROM ALABAMA AND MISSISSIPPI (DECAPODA: ASTACIDAE) Horton H. Hobbs, Jr. and Margaret Walton 37 4. HEAT DEATH AND ASSOCIATED WEIGHT LOSS OF THE OYSTER CRASSOSTREA MRGIXICA Milton Fingerman and Laurence D. Fairbanks 53 5. THE ODONATA OF LOUISIANA George H. Bick 69 6. ENDOCRINE CONTROL OF THE RED AND WHITE CHROMATOPHORES OF THE DWARF CRAWFISH, CAMBARELLUS SHUFELDTI Milton Fingerman 137 7. HORMONES CONTROLLING THE CHROMATOPHORES OF THE DWARF CRAWFISH, CAMBARELLUS SHU- FELDTI: THEIR SECRETION, STABILITY, AND SEPA- RATION BY FILTER PAPER ELECTROPHORESIS Milton Fingerman and Mildred E. Lowe 149 8. CYPRINID FISHES OF THE SUBGENUS CYPRINELLA OF NOTROPIS. III. VARIATION AND SUBSPECIES OF XOTROPIS VENUSTUS (GIRARD) Robert H. Gibbs, Jr. 173 9. THE EARLY DEVELOPMENT OF RANA CAPITO SE- VOSA E. Peter Volpe 205 10. VARIATION AND SUBSPECIES OF THE CRAWFISH ORCOXECTES PALMERl (FAXON) (DECAPODA, AS- TACIDAE) George Henry Penn 229 11. THE SKELETON SHRIMPS (CRUSTACEA: CAPREL- LIDAE) OF THE GULF OF MEXICO Joan E. Steinberg and Ellsworth C. Dougherty 265 12. THE SYSTEMATIC STATUS OF THE SUCKERS OF THE GENUS MOXOSTOMA FROM TEXAS, NEW xMEXI- CO AND MEXICO C. Richard Robins and Edward C. Raney 289 Printed in the U.S.A. at New Orleans, by Hauser Printing Co., Inc. 6-N n Volume :>, Number I March 18, 195" GAMBUSIA HETEROCHIR. A NEW POECILIID FISH FROM TEXAS, WITH AN ACCOUNT OF ITS HYBRIDIZATION WITH G. AFFINIS CLARK HUBBiS, DEl'AUJ Mi:\T OF ZOOLOGY. THE LMVL'KSITY OF TEXAiS, AU^Tiy, TEXAS TULANE UNIVERSITY NEW ORLEANS TULANE STUDIES IN ZOOLOGY is devoted primarily to the zoology of the waters and adjacent land areas of the Gulf of Mexico and the Caribbean Sea. Each number is issued separately and con- tains an individual study. As volumes are completed, title pages and tables of contents are distributed to institutions exchanging the entire series. Manuscripts submitted for publication are evaluated by the editor and by an editorial committee selected for each paper. Contributors need not be members of the Tulane University faculty. EDITORIAL COMMITTEE FOR THIS NUMBER Robert R. Miller, Curator of Fishes, Museum of Zoology, Uni- versity of Michigan, Ann Arbor, Michigan George S. Myers, Professor of Biology, Stanford University, Stanford, California Milton B. Trautman, Curator of Vertebrate Collections, Ohio State University, Columbus, Ohio Manuscripts should be submitted on good paper, as original type- written copy, double-spaced, and carefully corrected. Two carbon copies in addition to the original will help to expedite editing and assure more rapid publication. An abstract not exceeding three percent of the length of the original article must accompany each manuscript submitted. This will be trans- mitted to Biological Abstracts and any other abstracting journal speci- fied by the writer. Separate numbers or volumes may be purchased by individuals, but subscriptions are not accepted. Lists of papers published will be mailed on request. Authors may obtain copies for personal use at cost. Address all communications concerning exchanges, manuscripts, edi- torial matters, and orders for individual numbers or volumes to the editor. Remittances should be made payable to Tulane University. When citing this series authors are requested to use the following abbreviations: Tulane Stud. Zool. Price for this number: §0.30. George Henry Penn, Editor Meade Natural History Library, Tulane University, New Orleans, U. S. A. Assistant to the Editor: Don R. Boyer rjlUS. COWIP. ZOOL APRo U HARVARD GAMBUSIA HETEROCHIR. A NEW POECILIID FISH Fio?IHlV£RSlTl TEXAS, WITH AN ACCOUNT OF ITS HYBRIDIZATION"^""" WITH G. AFFINIS CLARK HUBBS, Department of Zoology, The University of Texas, Austin. Texas During the past decade a number of fishes have been described from Texas fresh-waters. Some of them have been known for years, but were not described until recently. Others, such as the new species of Gainbus:a described below, have not been recognized until recently. This new mosquitofish, apparently restricted to the headwaters of Clear Creek, Menard County, Texas, is separated by some 800 miles from the ranges of its nearest relatives. Many hybrids between this species and Gaynbitsia affinis ( Baird and Girard ) have been collected. The geographic distribution and morphologic variation of the hybrids is discussed. Material of the new species has been collected by the author, W. Gordon Craig, Theodosius Dobzhansky, Alvin E. Ellington, Sr., James D. French, Murray K. Muston, Kirk Strawn, and John E. Tilton. I also w.sh to thank Charles Wilkinson and H. Leslie Jones for per- mifsion to collect on their ranches. Dr. Billie L. Turner identified the plants. Mr. George G. Henderson, Jr., made the photographs. Miss Nancy Walker and Mrs. Jane Hubby made the drawings. Counts and measurements were made as detailed in Carl L. Hubbs and Lagler (1947). Names for gonopodial structures follow those g'ven by Carl L. Hubbs (1926). The schematic diagrams to deter- mine degree of hybridization are modified from those proposed by Anderson ( 1949). GAMBUSIA HETEROCHIR, sp. nov. Fig. 1 Material. — The type material consists of the 24.5 mm holotype (University of Michigan Museum of Zoology No. 170936) and 125 other specimens of 17 to 45 mm (UMMZ No. 170937, Stanford Uni- versity Nos. 46445 to 46451, United States National Museum No. 164573, Museum of Comparative Zoology, Harvard University No. 39684. Chicago Natural History Museum No. 61805, and Texas Nat- ural History Collection Nos. 3065 and 4652), all of which were seined on two occasions from the headspring of Clear Creek, Menard County, Texas, 10.4 miles west of Menard. The first of these collections was made on February 22, 1953, and the second on February 20, 1956. Many hybrids with G. affinis occur in both collections. Possibly some or all of the specimens designated as G. heterochir contain some genes from G. affinis. However, as introgression into G. heterochir appears to be uncommon and suspected hybrids are excluded from G. heterochir collections, I believe that most of the specimens con- sidered to be G. heterochir are not contaminated with G. affinis genes. Diagnosis. — A stocky species of Gambusia. The deep indentation on the upper margin of the male pectoral fin ( fig. 5 ) distinguishes Tulane Studies in Zoology Vol. 5 '• '% Figure 1. Gambnsia licterochir, sp. nov. 23 mm male; both from TNHC 4652. Left: 3o mm female; Right: No. 1 Huhbs: A New Poeciliid Fish 5 G. heterochir from all known gambusiine species. It also has the largest gonopodial elbow and bluntest gonopodial tip ( fig. 3 ) when compared with the other known gambusiines. Description. — A minimum of ten adult males and ten adult females were used for the descriptions. Up to 86 specimens were examined for characters used in the analysis of hybridization. Fin rays: dorsal 7 or 8 (rarely 9); branched caudal 14 (rarely 13 or 15); anal 9 (rarely 10); pelvic 6 (rarely 5); pectoral 13 to 15. Scales: lateral line 30 or 31; caudal peduncle 16; predorsal rows 15 or 16. The bluntly rounded head enters ( step-measurement ) standard length 3.7-3.8 times in adult males and 3.3-3.7 times in adult females. The depth at the back of the eye slightly exceeds the width. The gape is equal to or slightly exceeds the snout length. The head is scaled to the anterior margin of the eye. The anterior nostrils open at the posterior lip of the premaxillary groove; the posterior ones open dorsal and anterior to the eye. The lateral line pits on the head are more or less connected: a single large pit mesial and anterior to the posterior nostril; two connected mesial and posterior to the posterior nostril; a crescent shaped series posterior to the upper margin of the eye; a connected row on the posterior margin of the preopercle; an interrupted series of pits on the ventral margin of the preopercle and the mandible; and a connected series of small pits in front of the eye. The body is deep and rounded. The highest point on the dorsal profile is at or immediately anterior to the anterior dorsal base. The distance between the dorsal insertion and the posterior end of the hypural plate is contained 1.2 to 1.3 and 1.4 to 1.7 times in the pre- dorsal length of males and females respectively. The dorsal fin is rounded, its depressed length is contained 3.9 to 4.3 and 4.3 to 4.9 times in the standard length of males and females respectively. The caudal is rounded. The anal of females is rounded, that of males modified into a gonopodium. The pelvics are small and the inner ray is bound to the abdomen by a membrane. The pec- toral is rounded, the sixth and seventh rays the longest. The gonopodium of males is distinctive (fig. 3). The anterior branch of ray four reaches almost to the tip of the gonopodium. The two- to four-segmented elbow is longer than the longest modified spine of ray three and often overlaps the adjoining unmodified seg- ments of ray three. The distal serra on the posterior branch of ray four is distal to the elbow. The serrae are numerous and long. The terminal hook is pointed at the distal tip. The terminal hook" on the anterior branch of ray five is rounded. The distal segments of that ray meet the main axis of the gonopodium at an angle of more than 45°. Similar to other members of the G. nicara^uensis species group, the modified spines on ray three are sharply distinguished from the more proximal undifferentiated segments and the length of the longest spine is much less than the combined basal lengths. One or two of the proximal modified spines have recurved hooks. Tulane Studies in Zoology Vol. 5 M e n 0 r d Co Fig-ure 2. Map of the Clear Creek reg-ion. Collection localities desig- nated by "X". G. heterochir known only from headwaters of Clear Creek. Both pectorals of the males are modified. Rays two through five have a flattened region along the ray. The inner half of the ray does not enter into the flattened blade of rays three through five. The upper margin has a deep incision near its tip. Apparently this in- cision is to steady the gonopodium during intromission. The color pattern is distinctive. The midorsal coloration is not darker than that of the adjacent area; i.e., there is no middorsal stripe. A fine axial streak extends from the midline above the anus to the caudal base; however, there is no diffuse lateral band surrounding the axial streak. The subterminal dusky markings on the body scales are absent only on the abdominal scales. A large number of the sub- terminal dusky marks are darker and form black crescents, which are found on all but the predorsal scales. The fine postanal streak is darker than the adjacent subterminal dusky scale marks. In adult females the large black crescents, which extend on each side from in front of the anus to behind the anal origin, do not meet across the midventral line. These anal marks are absent in young and in adult males. The head ground color is similar to that of the body. A black mark at the upper corner of the opercle covers more than one scale. The weak suborb'tal bar does not reach to the corner of the pre- opercle. The lips are no darker than the adjoining parts of the head. The dark lateral line pits on the head have light edges. The dorsal has a median row of dark spots and the other fins are dusky to color- less. Relationships. — In his review of the genus Gambusiu, Carl L. Hubbs ( 1926) divided the genus into four subgenera (Heterophalliua Hubbs, Gavihnsia Poey, Arthrophallus Hubbs, and Scbizophalliis Hubbs ) . Krumholtz (1948) stated that Hubbs and Walker (unpublished ms) consider that two nominal species {af finis and holbrooki) , compris- ing the nominal subgenera Arthrophallus and Schizophallus respec- No. 1 Hubbs: A New Poeciliid Fish tively, regularly intergrade in nature and therefore are to be assigned to the same species. Carl L. Hubbs ( 1929) divided the subgenus Gamhusia into two species groups, nobilis and nicaraguensis. and re- viewed the former. In his 1926 paper he separated the species com- prising the two species groups by key item "h". Members of the G. njcaragiiensis group differ from those in the G. nobilis group in that the former have { 1 ) shorter distal spines on ray three of the gonopodium, ( 2 ) the dusky lateral band indistinct or developed only on the trunk, and ( 3 ) no dark markings on the anal. Garnbusia heterochir has the shorter distal spines on the third gonopodial ray and the dusky lateral band indistinct. In both characters it resembles the G. nicaraguensis species group. The females have the dark anal markings characteristic of the G. nobilis species group. I consider 5 post SPINES Figure 3. Camera lucida drawing-s of gonopodial tips: A (upper), G. heterochir from type locality; B (lower), G. af finis from Middle Valley Prong- of San Saba River. 8 Tulane Studies in Zoology Vol. 5 that G. heterochir evolved from the ancestral stock of G. nicaraguensis shortly after that stock separated from the ancestral stock of G. nobilis. Range. — Gambusia heterochir is known only from the headsprings of Clear Creek, Menard County, Texas, 10.4 miles west of Menard (fig. 2) and from one locality near the shore 350 yards east of the headsprings. Many other collections have been made in headwaters of the San Saba River in Menard and Schleicher counties, covering all known habitats and concentrating on habitats similar to that of the headsprings of Clear Creek. One of the collections is from the lower part of Clear Creek. None of these collections contains Gam- busia heterochir. I believe that G. heterochir once had a wide dis- tribution in Central Texas. Its range probably has been restricted because this species is unable to compete with G. affinis. Clark Hubbs and Springer (msj suggest that members of the G. nobilis species group have restricted ranges for the same reason. Ecology. — The headsprings of Clear Creek are now impounded. The upper and lower of three dams enclose a small body of water, the middle impounds the bulk of the water. Except for the upper reservoir and the adjacent part of the middle reservoir, the banks are covered with cattails. The collections were made in the cattail-free areas. Submerged and emergent vegetation was prolific in all im- pounded parts of Clear Creek. A dense growth of Ceratophyllutn sp. occurred in the headspring. A species of Ludivigia was found with the Ceratophyllum. Another Ceratophyllum bed occurred where the G.. heterochir was sampled 350 yards east of the headspring. A dense stand of Jussiaea sp., Distichlis sp., Typha latifolia. and Hydrocotyle umbellata ? also were found there. Dense growths of Myriophyllum sp., Potomogeton spp., Chara sp., and Coniuni fnaculatum occurred elsewhere, but no G. heterochir specimens were collected. I suspect that G. heterochir populations were correlated with factors that were associated with Ceratophyllutp beds. Daytime surface water tempera- tures varied between 18.3 and 20.6" C in February and between 27.0 and 31.0° C in July. Although temperatures near 21" C occurred at the bottom (6 inches below the surface) at both seasons, this prob- ably had little effect on the fish as they remained on the surface unless disturbed. Night temperatures were probably lower than those taken during daylight hours. The name heterochir is derived from the Greek heteros ( = differ- ent) and cheir ( ^ hand) for the distinctive shape of the pectoral fin. Hybridization with Gambi/sia affinis In his account of natural hybridization in poeciliid fishes, Carl L. Hubbs (1955), listed only two hybrid combinations in the genus Gambusia: between two members of the G. nicaraguensis species group and between G. nobilis and G. affinis. The hybrids discussed below constitute a third example, and are the first documented record of natural hybridization amongst gambusiines. The collections contain specimens of G. heterochir, G. affinis. and No. 1 Hubbs: A New Poeciliid Fish hybrids. The hybrids do not constitute a discrete intermediate group as described by Carl L. Hubbs, Hubbs, and Johnson ( 1943) for nat- ural Fi hybrids, but definitely grade into G. affinis and may grade into G. beterochir. Thus it appears likely that F;.. and or back crosses occur in the Clear Creek population and gene flow occurs between the two species. However, Clark Hubbs and Strawn ( in press ) and Clark Hubbs (1956) report ¥\ hybrids that are not always inter- mediate between their parental types. As the two parental species are included in different subgenera, the hybrids are easily recognized and a study of the hybrid swarm may be of value in the study of the selective advantages of hybrids. ^ ) Sides T Pre- Dorsal Streak () (I 0 Caudal Bar Anol Spot Figure 4. Coloi- codings for individuals in hybrid swarm. Lower numbers for G. affinis, higher for G. heterochir, intermediate for hybrids. All of the Gambiisia specimens in four collections have been ana- lyzed. The collections are; two from the headwaters of Clear Creek; one from the lower part of Clear Creek, 2.4 miles downstream from the hybrid swarm; and one from Middle Valley Prong of the San Saba River, 1 mile west of Ft. McKavett, 17 stream miles from the hybrid swarm. The two collections from the hybrid swarm were selected for obvious reasons. The Middle Valley Prong collection is typical of 10 Tulane Studies in Zoology Vol. 5 G. affinis populations in the area, contains many specimens, and is from a locality ecologically similar to the headwaters of Clear Creek. This collection should show the morphology of uncontaminated G. affinis. The collection from the lower reaches of Clear Creek was analyzed to determine if the introgressed population extends down- stream. The data from these four collections have been graphed ( figs. 6, 7 ) following the techniques proposed by Anderson (1949)- As poe- Fig'ure 5. Pectoral fin structure of male: A (upper), G. heferochir, from a 20 mm specimen from type locality; B (lower), G. affinis, from a 22 mm specimen from Middle Valley Prong- of San Saba River. No. 1 Hubhs: A Netv Poeciliid Fish 11 ciliids exhibit marked secondary sexual dimorphism the sexes are plotted separately. Only mature males are used since immature males approach females in many characteristics. Only females over 25 mm ( standard length ) are graphed because some color characteristics are not established until that size. For both sexes the ordinate is the head width added to the head depth (both at the back of the eye) divided by the standard length. The figures do not change appreci- > > > > > > 93 >>> o > > > > to > ^ >>l ^ >3I Figure 6a. Pictorialized scatter diagram of Gambnsia males (see text for explanation of coding). Samples from headwaters of Clear Creek. 12 Tidane Studies in Zoology Vol. 5 obilis species g'roup, with notes on their variation, ecology, and evolution. Hubbs, Clark and Kirk Strawn (in press). Relative variability of hybrids between the darters, Etheostoma spectabile and Percina caprodes. Evolutio)i. Krumholtz, Louis A. 1948. Repioduction in the western mosquito- fish, Gambiisia affinis affinis (Baird and Girard), and its use in mosquito control. Ecol. Monag)-., 18: 1-43. Abstract A new species of poeciliid fishes, Gambusia heterochir, re- stricted to the headwaters of Clear Creek, Menard County, Texas is described. Both pectoral fins have a pronounced groove to steady the gonopodium during intromission. The new species has formed a hybrid swarm with Ga))tbi(sia affinis. Introgression with G. lietcrochir appears negligible. Introgression is not found in near-by populations of G. affinis. S'A//^-/Vj^etd T\ Volume 5. Number 2 March 18, 1957 NEW CALANOID COPEPODS OF PONTELLA DANA AND LABIDOCERA LUBBOCK WITH NOTES ON THE DISTRIBUTION OF THE GENERA IN THE GULF OF MEXICO ABRAHAM FLEMINGER, OLiJ' II sin: in i\yi:sii(jA 'iioxs, UNITED yS'J'ATES I-ISH A.\D WILDLIFE SERVICE, GALVESTOy, TEXA.S TULANE UNIVERSITY NEW ORLEANS TULANE STUDIES IN ZOOLOGY is devoted primarily to the zoology of the waters and adjacent land areas of the Gulf of Mexico and the Caribbean Sea. Each number is issued separately and con- tains an individual study. As volumes are completed, title pages and tables of contents are distributed to institutions exchanging the entire series. Manuscripts submitted for publication are evaluated by the editor and by an editorial committee selected for each paper. Contributors need not be members of the Tulane University faculty. EDITORIAL COMMITTEE FOR THIS NUMBER Elisabeth Deichmann, Curator of Marine Invertebrates, Mu- seum of Comparative Zoology, Harvard University, Cambridge, Massachusetts Arthur G. Humes, Professor of Biology, Boston University, Boston, Massachusetts Thomas E. Bowman, Associate Curator of Marine Invertebrates, United States National Museum, Washington, D. C. Manuscripts should be submitted on good paper, as original type- written copy, double-spaced, and carefully corrected. Two carbon copies in addition to the original will help to expedite editing and assure more rapid publication. An abstract not exceeding three percent of the length of the original article must accompany each manuscript submitted. This will be trans- mitted to Biological Abstracts and any other abstracting journal speci- fied by the writer. Separate numbers or volumes may be purchased by individuals, but subscriptions are not accepted. Lists of papers published will be mailed on request. Authors may obtain copies for personal use at cost. Address all communications concerning exchanges, manuscripts, edi- torial matters, and orders for individual numbers or volumes to the editor. Remittances should be made payable to Tulane University. When citing this series authors are requested to use the following abbreviations: Tulane Stud. Zool. Price for this number: $0.30. George Henry Penn, Editor Meade Natural History Library, Tulane University, New Orleans, U. S. A. Assistant to the Editor: Don R. Boyer mmi APR 3 asi HARVARD UPERSiTY NEW CALANOID COPEPODS OF PONTELLA DANA AND ' LABIDOCERA LUBBOCK WITH NOTES ON THE DISTRIBUTION OF THE GENERA IN THE GULF OF MEXICO ABRAHAM FLEMINGER, Gidf Fishery Investigations, United States Fish and Wildlife Service, Galveston. Texas Two previously undescribed species of Pontella Dana and one of Labidocera Lubbock were found during studies on an extensive collec- tion of plankton samples from the Gulf of Mexico and a small number from the Cape Hatteras region. The plankton tows were made by the vessels ALASKA, ALBATROSS, and FISH HAWK, operating under the supervision of the U. S. Fish and Wildlife Service and its prede- cessors, the U. S. Commission of Fish and Fisheries and the U. S. Bureau of Fisheries, respectively. The ALBATROSS and the FISH HAWK were engaged in early oceanographic and fishery exploration cruises in the Gulf of Mexico and off Cape Hatteras, whereas the ALASKA recently conducted an oceanographic and biological survey of the Gulf of Mexico. Notes on the distribution of other species of the two genera found m these collections are presented following the description of the new species. The cruise patterns of the ALASKA, which provided the majority of the records, are available in the Reports of the Texas A. and M. Research Foundation ( 1952, 1955). FAMILY PONTELLIDAE PONTELLA DANA, 1846 PONTELLA MIMOCERAMI," sp. nov. ( Figures 1-13) Localities, MateriaL— Key West ( ALBATROSS, station number and collecting data not available, 1884, 55 males and females; sample taken between April 15-27 or May 7-10 in Key West Harbor according to Townsend's 1901 account of ship's activities; — FISH HAWK, station 7794, 26 December 1912, surface tow, one female). Coastal waters off Galveston, Texas (collected by writer in surface tows, 4 and 17 August 1954, two males). One mile southeast of Port Aransas (col- lected by Mr. R. J. Kemp, Texas Game and Fish Commission, in sur- face tow, 18 August 1956, one male). Lat. 34" 20' N., long. 75° 50' W., near Lookout Lightship off North Carolina (FISH HAWK, no station number, 3 September 1914, surface tow, one male, one female). Measurements. — All measurements made from dorsal view; cephalo- thorax measured along midsagittal plane from anteriormost margin of forehead to posterior margin of intersegmental fold between ' The name mimocerami refers to the close relationship between the new species and P. cerami Scott. 20 Tulane Studies in Zoology Vol. 5 Figures 1-13. Pontella mimocerami, sp. nov, : 1. male, dorsal view; 2. female, dorsal view; 3. male abdomen, lateral view; 4. male, fifth legs; 5. female, rostrum; 6. Female, abdomen, dorsal view; 7. male, rostrum; 8. female, abdomen, ventral view; 9. male, geniculate an- tenna (less proximal segments); 10. female, abdomen, lateral view; 11. female, fifth legs; 12. mandibular dentition. Pontella tenuiremis Giesbrecht: 13. mandibular dentition. All figures drawn with aid of camera lucida; fig. 2 of holotype, remaining figures, except fig. 13, of paratypes. No. 2 Fleminger: New Calanoid Copepods 21 thoracic segment V and genital segment; length of abdomen from anterior margin of genital segment to articulation between fifth inner- most seta and right f ureal ramus. Measurements made at lOOx mag- nification with aid of ocular micrometer; specimen immersed in aqueous solution of 50'"r glycerine; slender glass rods used to support cephalothorax and abdomen in horizontal position. Measurements include total length ( TL ) and cephalothorax-abdomen length ratio (CAR). 1. Acluh fetnale: ALBATROSS; 10 specimens selected at ran- dom, TL range 3.18-3.63 mm, mean with standard error 3.29 ± .052 mm, standard deviation 0.156 mm, CAR range 3.5-4.2:1, mean 3.7:1. FISH HAWK, station 7794; TL 3-46 mm, CAR 3.9:1. FISH HAWK, Lookout Lightship; TL 3.40 mm, CAR 4.0:1. 2. Adult male: ALBATROSS; 10 specimens selected at random, TL range 2.70-3. 18 mm, mean with standard error 2.95 ± .046 mm, standard deviation 0.138 mm, CAR range 2.9-3.5:1, mean 3.3:1. Galveston; two specimens, TL 2.98 mm, CAR 3.7:1; TL 2.46 mm, CAR 3.8:1. FISH HAWK, Lookout Lightship; TL 2.98 mm, CAR 3.6: 1. Diagnosis. — A population inhabiting coastal waters of the Gulf of Mexico and the temperate western North Atlantic Ocean in which the male is close to P. cerami Scott and the female is similar to P. tenui- remis Giesbrecht. Adult ]eniale: Differs from tenuirernis chiefly in details of ab- domen, fifth legs, and dentition of mandibular gnathal lobe. Abdomen with genital segment partially separated from following segment by faint, incomplete suture (figs. 2, 6, 10). Anterior por- tion of genital segment with latero-dorsal swellings; swelling of left side enlarged in holotype, extending laterad in two lobiform processes ( fig. 2 ) ; swelling of left side often a single reduced lobe similar to unilobed swelling on right side (fig. 6). Compound genital segment with greatest width posterior to suture, postero-ventral portion with moderate, rounded swelling (fig. 10). Anal segment narrower than preceding segment. Furcal rami normal, not attenuated, about one and one half times longer than maximum width (fig. 8). Fifth legs (fig. 11) with exopodite bearing total of six spiniform processes, one medial, two terminal, three lateral; all excepting medial process reduced and somewhat equal in length; medial process about twice as long as others. Endopodite typically with bifid apex, bi- furcation occasionally lacking; ramus not fused with basal segment 2. Mandibular gnathal lobe with six teeth, fifth dorsalmost tooth monocuspidate (fig. 12); in tenuirernis gnathal lobe with eight teeth, fifth dorsalmost tooth bicuspidate (fig. 13). Adult male: Differs from cerami with respect to thoracic segment V, geniculate antenna, and fifth legs. Thoracic segment V with terminal portions in both dorsal and 22 Tulane Studies in Zoology Vol. 5 lateral views not truncate (figs. 1, 3); processes in dorsal view ex- tending posteriad in triangular lappet somewhat rounded near apex, terminating in reduced spiniform apex. Segment 17 of geniculate antenna with elongated ridge appressed to segment 16; proximal portion of ridge with low widely-spaced denticles, distal portion with closely-spaced spiniform denticles. Ridge of segment 18 with proximal denticles of uniform size. Proximal ridge of fusion segment 19-21 with single row of denticles. Segments 22-25 perfectly fused (fig. 9). Chela of fifth legs ( fig. 4 ) slightly different from that in ceranii (vide Scott 1909: pi- 53, fig. 15); distal segment with blunt apex, irregular margins, and not arcate; proximal segment with small spine medial to large spine. Types Icf. Localities, Materials). — All deposited in USNM. Fe- male holotype, no. 99193, selected from material of ALBATROSS. Key West station. Paratypes: nos. 99194-99196, 99203. Further Description. — Female: rostrum lacking distinct lens ( fig. 5 ) ; first antennae with 24 segments; second antennae with endopodal segment 1 separated from basal segment 2; remaining appendages as in genus. Male: rostral lens weakly to moderately defined; length of rostral processes about equal to diameter of lens ( fig. 7 ) . Remarks. — Although the new species closely resembles the Indo- West Pacific species, cerami. this relationship is evident at present only in the male since the female of cerami is undescribed. However, the female of mifnocerami appears to be similar to the following predominantly Indo-Pacific species of Pontella, as described by Gies- brecht (1892: pis. 24, 40): tenuiremis: chierchiae Giesbrecht; jera Dana. The new species is distinguished in the male from the four species mentioned above by the following combined characteristics: (1) presence of an elongated, appressed, denticulated ridge on segment 17 of the geniculate antenna, the ridge completely overlapping the an- terior margin of the preceding segment; ( 2 ) absence of lamellar or triangular processes extending from the proximal segment of the chela; (3) triangular non-truncated condition of the terminal por- tions of thoracic segment V. In the female it can be separated by ( 1 ) the single medial spiniform process on the exopodite of the fifth legs, ( 2 ) the pair of lateral swellings on the antero-dorsal portion of the genital segment, ( 3 ) the ventral swelling posterior to the genital orifice, and (4) the simple, almost symmetrical, terminal portions of segment V. PONTELLA POLYDACTYLA,'- sp. nov. (Figures 14-24) Localities. Materials. — Key West ( ALBATROSS, same tow listed under preceding species, 16 males and females). - The name polyductijla refers to the many processes on the rami of the female's fifth legs. No. 2 Fleminger: Neiv Calanoid Copepods 23 Measurements. — All measurements made from right lateral view along imaginary straight line between limits; length of cephalothorax from anteriormost limit of forehead to posterior margin of inter- segmental fold between thoracic segment V and genital segment; length of abdomen from antero-dorsal margin of genital segment to distalmost margin of right furcal ramus. Otherwise, as already given under preceding species. 1. Adult female: 10 specimens; TL range 3.43-4.03 mm, mean with standard error 3-73 ± .062 mm, standard deviation 0.18 mm, CAR range 3.3-3-9:1, mean 3.5:1. 2. Adult male: 6 specimens; TL 3.64 mm, CAR 3.5:1; TL 3-76 mm, CAR 3-6:1; TL 3.85 mm, CAR 3-2:1; TL 3-75 mm, CAR 3-6:1; TL 3-54 mm, CAR 3-8:1; TL 3-71 mm, CAR 3-3:1. Diagnosis. — A robust species closely related to and strongly re- sembling P. lobiancoi ( Canu ) in dorsal view. Adult female: Differs from lobiancoi primarily in details of thoracic segment V, abdomen, and fifth legs. Posterior portions of thoracic segment V asymmetrical in dorsal view; right side triangular, left side truncate, each side with terminal styliform process extending posteriad beyond genital segment ( figs. 14, 18). Abdomen with three visible segments as in lobiancoi. Genital segment with short ventral process posterior and to left of genital orifice (figs. 15, 18); segment lacking postero-dorsal swelling. Second abdominal segment asymmetrical, right postero-ventral portion bear- ing a conspicuous swelling (figs. 14, 15); segment's ventral surface smooth, lacking lobules and papillae. Furcal rami in dorsal view somewhat axiniform rather than rectangular. Fifth legs with short thick rami; exopodite about as long as preced- ing segment, endopodite about as wide as long ( fig. 22 ) . Distal half of exopodite bearing six blunt spiniform processes, four distal- most overlapping. Endopodite terminating in two opposing pairs of short rounded processes. Adult male: Differs from lobiancoi chiefly in details of geniculate antenna and fifth legs. Geniculate antenna with segment 17 produced anteriad in robust irregular ridge; ridge armed with two, occasionally three, strong spines on proximal half, about six denticles on distal half. Ridge of segment 18 short, not reaching distal setae; denticles of ridge appear to be arranged in two rows, dorsal row with acuminate denticles, ventral row with lamelliform denticles. Two overlapping ridges of fusion segment 19-21 with robust denticles- Fusion segments 19-21 and 22-25 each terminating in a falcate spur (fig. 16)- Terminal segment of left fifth leg with acuminate apex flanked by two elongated lamellae; lamellae with unequal number of spinules on outer margin, unequal number of serrations on distal margin ( figs. 19, 20). Chela of right fifth leg with distal segment extending be- 24 Tulane Studies in Zoology Vol. 5 SCALE 0 S MM . 0 I MM ?IG§ 15,19,20,23 0.1 MM FIGS 16.21,22 17 male, dorsal view 18. temale, aoibai view, i , holotype, remaining figures of paratypes. No. 2 Pleminger: New Calanoid Copepods 25 yond falcate rhumb of proximal scgmenr; proximal segment wirh a somewhat digitiform process at midlength bearing one short medial spine (fig. 23). Types (cf. Localities, Material). — All types deposited in USNM. Female holotype, no. 99213, selected from material of ALBATROSS, Key West; paratypes, nos. 99214, 99215. Further Description. — Both sexes with rostrum lacking distinct lens (fig. 21). Forehead with pair of low rounded swellings just postero- mediad to dorsal subcuticular lenses (figs. 17, 18). First antennae except male geniculate antenna with 24 segments; in female antennae extending to anterior margin of thoracic segment V. Second antennae with first segment of exopodite incompletely separated from second basal segment; in female exopodite shorter than first segment of endopodite. Second basal segment of leg 4 lacking distal seta. Male in lateral view with terminal portion of thoracic segment V bearing a short spiniform process on left side, lacking on right side. Remain- ing appendages as in genus. Mated females with external lamelliform ornamentation, associated with spermatophore, enveloping genital segment; dorsal lamella with rectangular outline in dorsal view, covering dorsal surface of genital segment and overlapping right half of thoracic segment V; lateral lamellae fused with dorsal lamella, line of fusion sharp-edged; lateral lamellae extending mediad, overlapping ventral surface of genital segment. Remarks. — The new species is easily distinguished from all other known species of the genus in the female by the four-pronged en- dopodite of the fifth legs and the elongated styliform processes termi- nating thoracic segment V; in the male by the unusual form of the ridge and spines on segment 17 of the geniculate antenna and the pair of serrated lamellae on either side of the distal segment of the left fifth leg. The similarity between lohiancoi and the new species compels re- consideration of the former's records from the Gulf of Mexico and the western Atlantic reported by Wilson ( 1932, 1942, 1950) and by King (1950). Except for these records, lobiancoi is known to occur only in the Mediterranean Sea and in Western European waters, Wime- reux (Pas-de-Calais) being the type locality. It is noteworthy that this species was absent in the more than 200 samples collected by the ALASKA in the Gulf of Mexico. Considering the conspicuous, al- though superficial, resemblance between the two species and the usual occurrence of lobiancoi only in western European neritic waters, it seems best to regard Wilson's and King's records with reserve. The Species of Pontella in the Gulf of Mexico A qualitative analysis of more than 200 plankton samples collected by the ALASKA at surface stations scattered throughout the Gulf of Mexico revealed two known species of Pontella, meadi Wheeler and spinipes Giesbrecht, in addition to those described above. Geograph- 26 Tulane Studies in Zoology Vol. 5 ical records of Pontella obtained during the present study are pre- sented in Map 1. P. meadi occurred at six widely scattered neritic localities over the northern shelf between the Florida Keys and Port Isabel. In addi- tion, P. pennata Wilson was found together with meacU at all but one locality. The latter is not listed separately since there is considerable evidence ( unpublished ) that pennata is synonymous under meadi, a detailed account of this synonomy will be presented in a later paper. Previous records of meadi in the Gulf list the species from waters off western Florida (King 1950, Wilson 1950). Map 1. Records of species of the grenus Pontella collected by the M/V ALASKA in the Gulf of Mexico between April 1951-June 1953. Dots represent stations occupied by ALASKA. No. 2 Fleminger: New Calanoid Copepods 27 P. spinipes appeared to be the most widespread species of the genus in the Gulf. It was found in 18 samples, occurring most frequently at stations made in slope and oceanic waters. Although there are no previously published Gulf records of spinipes. Jones (1952) has listed it from the Florida Straits region. According to T. E. Bowman (personal communication, 1955; the species has also been observed at Dry Tortugas and in the Caribbean Sea. Moreover, I have found spinipes together with P. securijer Brady in samples taken by the F. W. S. M V OREGON just south of eastern Cuba (unpublished). Two other species of Pontella are purported to occur in the Gulf of Mexico. P. atlantica (Milne-Edwards) is questionably reported by Davis (1950), the determination based on a juvenile specimen taken off Rock Island, Florida. In addition, as already mentioned above, Wilson (1950) and King (1950) have listed lobtancoi from western Florida waters. LABI DOC ERA LUBBOCK, 1853 LABIDOCERA MIRABILIS,-^ sp. nov. (Figures 25-37) Localities. Material.— Florida. Keys: lat. 24° 43' N., long. 81° 57' W. (ALASKA, cruise 11, station 14, 5 June 1953, 10 m. depth of plankton tow); Key West (ALBATROSS, same tow listed under two preceding species); Knight's Key (FISH HAWK, station 7788, 19 December 1912, depth ?); Dry Tortugas (FISH HAWK, station 7794, 24 December 1912, depth ?). Total of 55 specimens includ- ing males, females, and immature copepodites found in above samples. Measurements. — All measurements made at 32x magnification from right lateral view, using methods described above under Pontella polydactyla. 1. Adult female: 11 specimens selected at random, TL range 2.54-2.95 mm, mean with standard error 2.80 ± .034 mm, standard deviation 0.109 mm, CAR range 3.5-4.2:1, mean 3.8:1. 2. Adult male: 18 specimens selected at random, TL range 2.21- 2.54 mm, mean with standard error 2.37 ± .026 mm, standard deviation 0.111 mm, CAR range 4.4-5.5:1, mean 5.1:1. Diagnosis.. — A distinctive species of moderate size from the Florida Keys region that resembles L. detruncata ( Dana ) . Adult female: Differs from detruncata primarily in details of thoracic segment V, abdomen, and fifth legs. Thoracic segment IV separated from segment V; terminal portions of V asymmetrical, right side extending farther laterad than left side and bearing larger spiniform process (fig. 28). Abdomen with two segments. Genital segment asymmetrical, bear- ^ The name iniruhiU^ refers to the unique leng:th relationship be- tween the exopodite and endopodite of the female's fifth legs. 28 Tulane Studies in Zoology Vol. 5 ing swelling on left side extending postero-laterad; genital orifice situated on postero-dorsal portion of swelling (figs. 27, 28). Anal segment not reduced. Furcal rami asymmetrical, right ramus longer SCALE 0.1 MM FIGS 25.30.31 0 I MM FIGS 27-29.32,34-36 0 1 MM . FIGS 26.33 Figures 25-37. Labidocera mirahilis, sp. nov. : 25. female, lateral view; 26. female, fifth legs; 27. female, abdomen, lateral view; 28. fe- male abdomen, dorsal view; 29. female, abdomen with spermatophore and ornamentation, lateral view; 30. male, dorsal view; 31. male, lateral view; 32. male, fifth legs; 33. male, left fifth leg, terminal segment; 34. female, abdomen with spermatophore and ornamenta- tion, dorsal view; 35. female, forehead, dorsal view; 36. male, genicu- late antenna (less proximal segments) ; 37. mandibular dentition. All figures drawn with aid of camera lucida; figs. 25, 26, 29, 34, 35 of holotype, remaining figures of paratypes. No. 2 Fleminger: New Calanoid Copepods 29 and broader than left (fig. 28). Fifth legs differ from those of all known species of Labidocera; endopodite longer than exopodite, ratio of former to latter about 1.8:1 (fig. 26). Exopodite with total of three shore spiniform pro- cesses, one lateral, two apical. Endopodite moderately constricted midway in length, distal half curving mediad. Adult male: Differs from detruncata in details of thoracic segment V, geniculate antenna, and fifth legs. Thoracic segment V asymmetrical, right side with short spiniform process, left side rounded ( figs. 30, 31)- Geniculate antenna (fig. 36) with ridge on segment 17 produced in robust ovate lobe bearing two marginal rows of five to eight den- ticles; denticles of dorsal row robust, those of ventral row minute. Ridge of segment 18 short, terminating at approximate midlength of segment; ridge armed with about 25 short blunt denticles. Fusion segment 19-21 with two slightly overlapping ridges, each ridge bearing blunt closely-spaced denticles. Segment 22 with distal falcate spur. Left fifth leg with short ramus superficially unisegmental; short distal segment hirsute, partially fused to proximal segment and ex- tending laterad (fig. 32); distal segment with posterior ridge and short digitiform apex offset laterad; ridge with multilobed distal mar- gin (fig. 33). Chela of right leg with more elongated proximal seg- ment than that in detruncata: distal segment with proximal triangular process bearing two spines and distal low lamella (fig. 32). Types icj. Localities. Material). — All deposited in USNM. Female holotype, no 99207, selected from material of ALASKA, cruise 11, station 14. Paratypes: nos. 99208-99212. Further Description. — First antennae in female with 24 segments. Second antennae with basal segment 2 fused with segment 1 of en- dopodite. Remaining cephalic and thoracic appendages as in genus. Mated females with abdomen obscured by complex lamelliform ornamentation associated with spermatophore ( figs. 29, 34 ) ; orna- mentation with somewhat rectangular basal plate ventral to genital segment and bearing a short ventral process at each corner; basal plate also supporting lateral lamellae which extend dorsad; those of right side larger, anterior one curving laterad, posterior one curving mediad; left side with two smaller lamellae, anterior one extending mediad, posterior one extending laterad. Re??iarks. — The new species is readily distinguished from all other known species of the genus. The female is best characterized by the fifth legs, in which the endopodite is almost twice the length of the exopodite. and by the asymmetrical genital segment, bearing the geni- tal orifice latero-dorsad on a left lateral swelling. In the male the left fifth leg and the geniculate antenna possess ex- cellent diagnostic features. The left fifth leg is superficially uniseg- mental with the terminal portion hirsute and turned laterad in a short truncate process. With respect to the geniculate antenna, segment 17 bears two rows of five-eight spines each, the dorsal spines being more 30 Tulane Studies in Zoology Vol. 5 than three times the size of the ventral spines, and segment 23 termi- nates in a robust falcate spur. The Species of Labidocera in the Gulf of Mexico In addition to mirabilis. four other species of the genus, acutifrons (Dana), aestii'a Wheeler, neri (Kr0yer), and scotfi Giesbrecht, occur in the Gulf of Mexico. The local range of each of these species as determined from the ALASKA plankton collections is presented be- low ( Map. 2 ) . Map 2. Records of the jj-enus Labidocera collected by the M/V ALASKA in the Gulf of Mexico between April 1951-June 1953. Dots represent stations occupied by ALASKA. No. 2 Fleminger: New Calanoid Copepods 31 L. acutifrons occurred at 13 oceanic localities east of long. 90^ W., two oceanic localities south of Atchafalaya Bay, and two outer neritic localities off Laguna Madre. Included in this group are captures made in the mouth of the Yucatan Channel, in the vicinity of the Florida Keys, and off northern Cuba. Previous Gulf localities reported for the species are limited to the coastal waters off the southern half of Florida (King 1950). L. aestira. the most abundant species of Pontellidae in the collec- tions, was confined almost exclusively to northern neritic waters be- tween Florida and Laguna Madre. Numerically, the species was highly concentrated between Appalachicola Bay and the East Texas coast. Beyond these limits aestiva was taken in very small numbers, often only one or two specimens per standard tow.^ A single speci- men was also obtained from a tow made just off northern Yucatan. Both Davis (1950) and King (1950) have previously listed the species from the waters off western Florida. L. neri was found at two localities, one in the vicinity of Key West and the other at about lat. 27° N., long. 86° W. The species has not been reported previously from the Gulf region. L. scotti occurred at 17 ALASKA stations confined to or near neritic waters, including 14 coastal localities between the Lake Charles- Campeche area, one just off northeastern Yucatan, and two in coastal water off Florida, at Tampa and Key West, respectively. In addition, several records from Galveston, southern Florida, and the Florida Keys were established during the present study from collections by the ALBATROSS and the FISH HAWK as well as from material col- lected off Texas by the writer. The species was not found within the central portion of aestiva's range ( Cape San Bias-Lake Charles ) . However, both species broadly overlap in the northeastern and north- western sections of the Gulf. It is noteworthy that in the western overlap zone the number of scotti individuals per standard tow fell off gradually in the more northern samples. Conversely, aestiva showed a similar reduction in more southern tows with only single specimens per tow appearing in the Padre Island-Laguna Madre ( Mexico ) region. Gradual displacement of aestiva by scotti also appears to occur pro- ceeding south along the West Florida coast. The ALASKA material presents little evidence of a shift in the numbers of each species because of inadequate coverage of inshore areas in the region. How- ever, Davis (1950) studying the plankton of the entire coast of western and southern Florida found scotti to be the most abundant and widespread species of Lahidocera along the west coast. Around the southern tip of Florida, particularly within Biscayne Bay, extensive sampling both seasonally and geographically by two investigators (Davis 1950, Woodmansee 1949) have firmly established the year- ^ A 30 minute horizontal tow at 1 meter depth with one half meter net, No. 10 mesh. 32 Tulane Studies in Zoology Vol. 5 round presence of scotti. In contrast, aesiiva was not found during these studies, nor did it occur in the inshore collections made in Florida Bay by Davis and Williams ( 1950). At first glance. King's ( 1950) plankton survey of the entire west coast of Florida, in which aestiva and acutijrons are the only species of Labidocera listed, would appear to contradict Davis' results. How- ever, scotti is not described or mentioned in the literature of those copepod specialists referred to by King as his source for specific identifications. Therefore, it is probable that King was unfamiliar with scotti and possibly confused it with aestiva. It is interesting that the distributional patterns outlined by the available data on aestiva and scotti in the Gulf of Mexico conform closely with the two principle temperature zones of the region. Ekman (1953) and Hedgpeth (1953) have noted that with the exception of the southern half of both Texas and Florida the neritic waters off the Gulf states are characterized by warm temperature conditions (> 10' -ca. 25^ C). For example, within the region in which aestiva predominates, the moUuscan fauna is predominantly Carolinian ( Rehder 1954) and Crassostrea virginica (Gmelin) occurs as a com- munity dominant (Ekman 1953). The remaining neritic waters of the Gulf, with scotti the predominant species of the genus, apparently transcend from subtropical to tropical conditions ( ca. 20° - > 25° C), culminating in the presence of coral reefs in the Tampico, Vera Cruz, Campeche, and Yucantan areas (Walton Smith 1954). Thus, in the Gulf the two species appear to be planktonic indicators of the two respective coastal water zones. Since they also fulfill adequately the physical requirements for planktonic indicator species ( large size, singular appearance, high relative abundance, etc. ) , they should be subjected to more detailed study. Apart from the Gulf, temperatures characteristic of the known range of each species are remarkably similar to conditions within the local Gulf range. L. aestiva is a well established inhabitant of tem- perate coastal waters between northern Florida and the Gulf of St. Lawrence (type locality: Woods Hole, Massachusetts). It has also been recorded from Brazilian coastal waters ( Carvalho 1945, 1952; Oliveira 1946), but the existence of three other species in this area {fluviatilus Dahl, darwini Lubbock, braziliense Farran ) that are very similar to aestiva casts some doubt on the validity of these reports. In contrast, scotti is known only from the tropical or near-tropical waters off the African west coast (type locality: Gulf of Guinea). In summary, at least five species of the genus Labidocera are repre- sented in the Gulf of Mexico. Regarding the three most abundant and widespread of these species, each appears to predominate in a different environmental area: acutijrons is found throughout the oceanic region, aestiva occurs along the northern temperate coastal area, and scotti is representative of the tropical or near-tropical coastal area. No. 2 Fleminger: New Calanoid Copepods 33 Although, admittedly, data on Pontella in the Gulf of Mexico are sparse, the available information suggests that, as in Labidocera, the species tend to be environmentally separated as follows: meadi — warm-temperate neritic, mimocerami — tropical neritic, and spitjipes — tropical oceanic. The remaining species, P. polydactylu. L. neri and L. 7nirabilis, appear to be infrequent transients in the easternmost por- tions of the Gulf region. References Cited Carvalho, J. DE P. 1945. Copepodos de Caioba e baia de Guaratuba. Arq. Mus. Paranae7ise Ciin'tiba, 4: 83-116, pis. 6-12. 1952. Sobre uma Colecao de Copepodos nao para- siticos da Baia de Santos e suas adjacencias. Bol. Inst. Oceanogr., Univ. Sao Paulo, 3: 131-188. Davis, C. C. 1950. Observations of plankton taken in marine waters of Florida in 1947 and 1948. Quart Jonr. Fla. Acad. Sci., 12: 67- 103. and R. H. Williams 1950. Brackish water plank- ton of mangrove areas in southern Florida. Ecology, 31: 519-531, 1 fig. Ekman, S. 1953. Zoogeography of the Sea. Sedgwick and Jackson, London, 417 pp., 121 figs. GlESBRECHT, W. 1892. Systematik und Faunistik der Pelagischen Co- pepoden des Golfes von Neapel. Fauna u. Flora Golf. Neapel, 19: 1-831, 54 pis. Hedgpeth, J. S. 1953. An introduction to the zoogeography of the northwestern Gulf of Me.xico with reference to the invertebrate fauna. Publ. Inst. Mar. Sci., Univ. Texas, 3: 106-224, 46 figs. Jones, E. C. 1952. A preliminary survey of the copepods of the Flori- da Current. (Unpublished Master of Arts thesis. University of Miami.) King, J. E. 1950. A preliminary report on the plankton of the west coast of Florida. Quart Jour. Fla. Acad. Sci., 12: 109-137. Oliveira, L. p. H. 1946. Estudo sobre o Microplancton capturado durante a viagem do navio hidrografico Lahmeyer nas baias de Ihla Grande e Sepetiba. Mem. Inst. Oswaldo Cruz, 44: 441-488, 7 pis., 14 figs. Rehder, H. a. 1954. Mollusks. Fish. Bull., Fish and Wildl. Sen-., 55: 469-474 (Fishery Bull. 89). Scott, A. 1909. Copepoda of the SIBOGA Expedition. Pt. 1. Free- swimming, littoral, and semi-parasitic Copepoda. SIBOGA Ex- ped., 29a: 1-323, 69 pis. Smith, F. G. W. 1954. Gulf of Mexico Madreporaria. Fish. Bull.. Fish and Wildl. Serv., 55: 291-295 (Fishery Bull. 89). Texas A. and M. Research Foundation. 1952. Oceanographic sur- vey of the Gulf of Mexico, annual report for 1952. Status report ( Mimeographed. ) 1955. Oceanographic survey of the Gulf of Mexico. Physical and meteorological data. Data report No. 3. (Mimeo- graphed.) Townsend, C. H. 1901. Dredging and other records of the steamer ALBATROSS with bibliogi-aphy relative to the work of the vessel. Rept. Commissioner, U. S. Comm. Fish., 1900, pt. 26: 389-500. 34 T :ilane Studies in Zoology Vol. 5 Wilson, C. B. 1932. The copepods of the Woods Hole reg-ion, Massa- chusetts. Bull. U. S. Xat. Mus., 158: 1-635, 41 pis., 316 figs. 1942. Sci. Res. of Cruise VII of the CARNEGIE during' 1928-1929. Biol. I. The copepods ot the plankton gathered during the last cruise of the CARNEGIE. Carnegie Inst., Wash- ington, Piihl. 536: 1-237, 136 figs. 1950. Copepods gathered by the U. S. Fish, steamer ALBATROSS from 1887 to 1909, chiefly in the Pacific Ocean. Bull. U. S. Nat. Mtis., 100, 14: 141-441, pis. 2-36. WooDMANSEE, R. A. 1949. The zooplankton off Chicken Key in Bis- cay ne Bay, Florida. (Unpublished Master of Arts thesis. Uni- versity of Miami.) Abstract Descriptions are presented for three new calanoid copepods taken in the Gulf of Mexico during plankton collecting opera- tions of the U. S. Fish and Wildlife Service: Pontella minw- cerami, n. sp., is related to P. cerami Scott; P. polydactyla, n. sp., is close to P. lohiancoi (Canu) ; Labadocera mi)-abilis, n. sp., resembles L. detrnncata (Dana). Records of previously known species of Po)itella Dana and Lahidocera Lubbock that appeared in the numerous plankton samples under consideration are charted. Their distributional patterns in the Gulf of Mexico are discussed. From the avail- able evidence the more abundant and widespread of the species within each genus tend to be separated environmen- tally from one another. In Labidocera, aestiva Wheeler is temperate-neritic, scotti Giesbrecht is tropical-neritic, and acutifrons (Dana) is tropical-oceanic. In Pontella, meadi Wheeler is temperate-neritic, mintoceratni is ti'opical-neritic, and spinipes Giesbrecht is tropical-oceanic. The remaining species, Pontella polydactyla, Labidocera )ieri (Kr0yer), and L. mirabilis appear to be transients in the easternmost por- tions of the Gulf region. ^^/v/4 -u^ J ilBRARY iAPR3 19§t urn ^(D(DiL®(§ir Volume 5, Number 3 March 18, 1957 THREE NEW CRAYFISHES FROM ALABAMA AND MISSISSIPPI (Decapoda: Astacidae) HORTON H. HOBBS, JR., DEPARTMENT OF BIOLOGY, lMyERt