18 September 1998 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 111(3):634-644. 1998. A new genus and species of "goneplacid-like" brachyuran crab (Crustacea: Decapoda) from the Gulf of California, Mexico, and a proposal for the use of the family Pseudorhombilidae Alcock, 1900

Michel E. Hendrickx Institute de Ciencias del Mar y Limnologfa, Estacion Mazatlan, UNAM. P.O. Box 811, Mazatlan, Sinaloa 82000, Mexico

Abstract.—A new genus and species of crab, Bathyrhombila furcata, are described from localities in the Gulf of California, western coast of Mexico. The new genus is close to Pseudorhombila H. Milne Edwards and belongs to a group of three genera tentatively assigned to the subfamily Pseudorhombi- linae Alcock, 1900 by Guinot in 1969. The affinity of Bathyrhombila, new genus, with other genera of "Goneplacidae" {Euphrosynoplax Guinot, Pseu­ dorhombila H. Milne Edwards, Nanoplax Guinot, Oediplax Rathbun, and Cha- cellus Guinot) is discussed, noting that they all represent primitive transitional forms between the cyclometopous and the catometopous abdomen-sternum or­ ganization, and a similar "xanthoid-goneplacid" facies. On the basis of these affinities, it is proposed that these six genera be included into the family Pseu­ dorhombilidae Alcock, within the Heterotremata Guinot, 1977. Resumen.—Se describe un nuevo genero y una nueva especie de cangrejo, Bathyrhombila furcata, recolectado en localidades de el golfo de California, costa oeste de Mexico. El nuevo genero se parece a Pseudorhombila H. Milne Edwards y pertenece a un grupo de tres generos tentativamente asignados a la subfamilia Pseudorhombilidae Alcock, 1900 por Guinot en 1969. Se discute la afinidad de Bathyrhombila, nuevo genero, con otros genero de "Goneplacidae" (Euphrosynoplax Guinot, Pseudorhombila H. Milne-Edwards, Nanoplax Guin­ ot, Oediplax Rathbun, y Chacellus Guinot), senalando que todos ellos repre- sentan formas primitivas de transicion entre la organizacion abdomen-estemon cyclometopes y catametopes, y una apariencia similar de tipo "xanthoideo- goneplacideo". En base a estas afinidades, se propone que estos seis generos sean incluidos en la familia Pseudorhombilidae Alcock, dentro del grupo de los Heterotremata Guinot, 1977.

Two common and widely distributed Xanthoidea proposed by Guinot (1978) em- families of brachyuran crabs, the Xanthidae phasized the sternal position of female and Goneplacidae (sensu Balss 1957) have openings ("sternitremes") coupled with the long been recognized as containing hetero- coxal or coxo-stemal position of male gen- geneous groups of genera (see Guinot 1970, ital openings, thus relating the Xanthoidea 1977, 1978; Serene 1984; Williams 1984; with the heterotremateous arrangement Martin & Abele 1986). In the last twenty (Heterotremata, as defined by Guinot 1977). years, the organization of the Xanthidae Guinot (1978) insisted on the fact that sensu Balss has been subject to many among the Xanthoidea, two groups of fam- changes. The concept of a superfamily ilies should be considered: one with male VOLUME 111, NUMBER 3 635

opening coxal, and another in which the entre Cyclometopes et Catometopes [an or­ male opening progressively migrates to a ganization close to the cyclometopous or­ coxo-stemal position. In the later group, the ganization and probably belonging to the evolutionary process is associated with a crabs linking the cyclometopous to the ca- modification of the facies, which becomes tametopous]." A second species of Chacel­ goneplacid-like (Guinot 1978:266). Guinot lus was added by Hendrickx (1989a) who, (1978) also suggested that when all genera despite of a "rather xanthoid facies," in­ of Goneplacidae sensu Balss will have been cluded it in the Goneplacidae with a "prim­ reviewed, new families might be added to itive catometopous organization." Another the second, goneplacid-like group of Xan- genus, Euphrosynoplax Guinot, 1969b was thoidea (i.e., those genera with a coxo-ster- also described by Guinot (1969b:720), to nal male openings). accommodate an undescribed species of A group of goneplacid-like brachyuran crab from Florida: E. clausa Guinot, 1969b. crabs presently included in the Goneplaci­ Again, Guinot (1969b) emphasized the dae has long been recognized as represent­ primitive catometopous stage of this genus, ing an intermediate step towards the trans­ relatively close to the cyclometopous ar­ formation of the cyclometopous (heterotre- rangement. A second species of Euphrosy­ matous) abdomen-sternum arrangement noplax was recently described by Vazquez- (male genital opening coxal; abdominal so­ Bader & Gracia (1991) from the Gulf of mites 1-2 covering entirely the space be­ Mexico. Although these authors did not tween the coxa of P5; stemite plate 8 en­ clearly illustrate stemite eight, they refer to tirely covered by these abdominal somites a (what appears as a primitive) catometo­ and not visible ventrally) into a catometo­ pous organization of their species, E. cam- pous arrangement (male opening sternal; pechiensis, with a ". . . male opening coxal stemite plates 7 and 8 widened, ventrally [and] a small portion of stemite 8 not cov­ united and visible ventrally; abdominal seg­ ered by the second abdominal somite." ments 1-2 reduced, clearly separated from coxa of P5) (Guinot 1969a, 1978, 1979). The present paper deals with a new spe­ For Guinot (1969b, 1970) this group of cies of crab that present morphological sim­ genera represents an evolutionary step to­ ilarities with those in the above cited gen­ wards the more advanced catometopous era. It is herein considered that this new (thoracotrematous) organization in which species requires a new genus. Furthermore, the sternum occupies an increasingly wider the use of the family Pseudorhombilidae area between the basal abdominal somites Alcock, 1900, is proposed for a group of and the coxa of P5, and the male opening six genera with a "xanthoid-goneplacid" moves progressively towards a sternal po­ facies representing primitive transitional sition. Guinot (1970: 1076, 1080) suggested forms between the cyclometopous and the that several of these genera (i.e., Pseudo- catometopous abdomen-sternum organiza­ rhombila H. Milne Edwards, 1837, Oedi- tion. plax Rathbun, 1893, and possibly Nanoplax Abbreviations used in this paper are: CW, Guinot, 1967) could be integrated in the carapace width; CL, carapace length; P2 to subfamily Pseudorhombilidae Alcock, 1900 P5, pereiopods; Pll and P12, male first and pro parte. second pleopods (gonopods), respectively; Guinot (1969b: 721) also described the SEM, Scanning Electron Microscope; genus Chacellus Guinot, 1969b, monotypic EMU, Estacion Mazatlan UNAM, inverte­ at that time, which she considered "... [a brate reference collection; SIO, SCRIPPS genus with] une organisation tres proche de Institution of Oceanography, invertebrates r organisation cyclometopienne et fait sans collection. La Jolla, California, U.S.A.; doute partie des Crabes formant le passage LACM, Los Angeles County Museum of r 16 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

atural History, Los Angeles, California, curved, gap between fingers reduced. A .S.A. very conspicuous, strong pterygostomian Drawings were made with a camera lu- ridge in front of cheliped articulation. Lda (Fig. 2). Holotype was photographed Walking legs slender, long, flattened. Ster­ sing a Kodak TMAX 100 ASA black and num moderately wide, narrowing in front of ^hite film (Fig. 1), and SEM microphoto- PI. Abdomen narrow in its base; segment raphs of male gonopods were obtained us- 2 not overlapping coxa of P5. Abdominal ig the classical technique of acetone de- segments 3-5 incompletely fused; suture 3- ydrated, gold-palladium coated gonopods 4 distinguishable, a remaining notch on xtracted from type material (Fig. 3). both extremities; suture 4-5 obsolete, a re­ maining notch on both extremities. A small portion of stemite 8 visible, close to artic­ Bathyrhombila, new genus ular condyle of P5, not in contact with ster- Diagnosis.—Carapace 1.4 to 1.5 broader nite plate 7. A shallow depresion in front lan long, anteriorly convex, slightly con- of the abdominal telson. Male genital open­ ex and narrower posteriorly; general shape ing coxal and gonopod 1 free. Pll long, xanthoid". Antero-lateral margin arched, slender, with slightly curved apex; stiff sub- /ith 4 teeth, excluding the outer orbital terminal spines, with stout and long lateral 5oth which is well-defined and slightly (apical) process and shorter, hook-like api­ rejecting; second and outer orbital teeth cal process. P12 short, sigmoid. used, forming an almost straight slightly Type species.—Bathyrhombila furcata, rejecting margin; length of this margin al- new species, by original designation and lost half the frontal width. Postero-lateral monotypy. order converging posteriorly. Regions rel- Ethymology.—The name of the genus is tively well marked. Front narrow, less than a combination of rhombila and bathys, to } maximum width of carapace, slightly indicate affinities with the genus Pseudo- rejecting forwards, with a shallow median rhombila H. Milne Edwards and the fact epression, margin sinuous, with a well- that most specimens were collected in the larked notch between the external comer bathybenthic region. nd the inner orbital tooth. Orbits reduced 1 size; eyes relatively small. Upper orbital Bathyrhombila furcata, new species largin slightly concave, with 2 distinct su- Figs 1-3 jres; lower orbital margin with 2 strong jeth, inner one acute, outer one rounded, Material examined.—Holotype, male kntennal flagellum long, entering orbit; ba- (CW 24.6 mm; CL 17.5 mm), 05 Jul 1965, al article of antenna relatively long, slight- station SIO 65-257, La Paz Bay (24°19'N, ^ oblique, in contact with front; a small 110°26'W), Baja California, Mexico, otter pophyse intercalated between basal article trawl, 55-80 m (coll. W. Baldwin) (SIO C- nd epistome (pterygostomian upper bor­ 2116). er); palp folding horizontaly. Interanten- Paratypes: male (CW 20.3 mm; CL 14.45 ular septum broadly triangular. Third max- mm), 18 Jan 1968, station MV68-I-59, Gulf liped with merus about 0.5 times length of of California, north of Angel de La Guarda ichium, antero-extemal angle slightly pro- Island (29°41'N, 113°56'W), Baja Califor­ uced; palp articulating at inner distal angle nia, Mexico, 566-644 m, otter trawl, RA^ f merus. Chelipeds large and robust, not T. Washington (coll. C. Hubbs) (SIO C- larkedly unequal in large males, subequal 5669A). Male, sUghtly damaged (CW 22.8 1 females; carpus with a blunt, moderately mm; CL 16.35 mm), 18 Jan 1968, station irge spine at inner angle; pincers very MV68-I-59, Gulf of California, north of irge, fingers flattened, pointed, tips re­ Angel de La Guarda Island (29°41'N, r VOLUME 111, NUMBER 3 637 113°56'W), Baja California, Mexico, 566- long (length of major claw about equal to 644 m, otter trawl, RA'^ T. Washington CW), right claw being slightly higher (coll. C. Hubbs) (LACM-68-464.1, ex-SIO (right/left claw maximum height ratio 1.09 C-5669). to 1.12). Merus with granules on anterior Non-paratypes: 1 soft shell male (cw and posterior sides, a dorsal row of granules 25.95 mm; CL 17.95 mm), 1 damaged soft- and a blunt superior subterminal angle, pro­ shell ovigerous female (CW ca. 17.9 mm; duced in a low tubercle. Carpus strong, CL ca. 13.0 mm), 18 Jan 1968, station obliquely subquadrate in dorsal view, sur­ MV68-I-59, Gulf of Cahfomia, north of face slightly irregular dorsally; clusters of Angel de La Guarda Island (29°41'N, granules arranged in rugae (well defined in 113°56'W), Baja California, Mexico, 566- the holotype) on outer slope; a blunt, mod­ 644 m, otter trawl, RA'^ T. Washington erately large spine at inner angle; a well- (coll. C. Hubbs) (SIO-5669C). defined sulcus parallel to distal border. Ma- Description.—Carapace wide (CW/CL nus inflated, smooth (microscopically punc­ ratio 1.40-1.46). Front narrow (7.05 mm tated). Fingers long, flattened, pointed, wide in holotype), sinuous; fronto-orbital strongly incurving and with recurved tips, width (13.4 mm in holotype) about half the gap between fingers reduced; length of dac- carapace width. Carapace anteriorly convex tylus of major claw ca. 0.4 times length of and mostly covered with small flattened claw; dorsal margin of dactylus of major granules, without setae; granules more nu­ claw almost straight, that of major claw merous and rounded close to edges and on only slightly curved. Cutting edge of dac­ antero-lateral teeth. Antero-lateral margin tylus of both claws sharp, that of major with five teeth (including the outerorbital claw with a strong, projecting subrectan- tooth), the posterior three large to medium- gular proximal tooth, followed by a series sized, conical; second teeth reduced, fused of irregular, smaller teeth; cutting edge of with the outerorbital tooth and forming an polex with a series of irregular teeth; cut­ almost straight, little projecting margin; ting edges of smaller claw with reduced outerorbital tooth little produced, distinct. teeth. Fifth tooth smaller than the preceeding two; Pereiopods 2-5 long, slender, flattened; fourth teeth acute, pointing upward; third merus covered with dense granules on low­ teeth wider that fourth and fifth, its sides at er and upper margin, sides almost smooth; a right angle, flattened compared to fourth. carpus and propodus partly covered with Orbital lobe well-marked; upper orbital granules on upper margin; a low, longitu­ margin somewhat irregular, with small dinal granulated crest on upper margin of rounded granules and two conspicuous su­ carpus; dactylus about same length as prop­ tures (median and lateral); lower orbital odus, with longitudinal rows of setae, tip margin with granulated inner tooth and out­ short, corneous. Pereiopods 2-4 subequal er lobe, both granulated. Outer orbital tooth in length (P2 = 1.66 times CW; P3 = 1.69 well-defined, little projecting. Pterygosto- times CW; P4 = 1.63 times CW), fifth pe- mian and subhepatic regions granulated. reiopod notably shorter (1.39 times CW). Pterygostomian ridge coarsely granulated. A small portion of stemite eight of male Distal border of merus of third maxilli- abdomen visible between second and third ped sinuous, with a marked median concav­ abdominal somites; first and third somites ity; antero-extemal angle little produced; slightly wider than second, second and third merus coarsely granulated; ischium with of about the same length and with subacute more flattened granules, its distal border lateral margins; sixth somite wider than produced internally in a lobe; palp coarse. long, sides concave, narrower medially, dis­ Cheliped very strong, long (length of ma­ tal and proximal margin equal; seventh so­ jor cheliped ca. 1.75 CW); claw heavy and mite (telson) as long as sixth, posteriorly 638 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

Fig. 1. Holotype, male, CW 24.6 mm, CL 17.5 mm, dorsal view. La Paz Bay, Baja California, Mexico (SIC C-2116).

rounded. First somite and hteral portion of o/tAe smallest whereas It Is 1.11 In the ho- second coarsely granulated; other somites lotype. The soft-shell male is also the larg­ with fewer flattened granules or almost est male available but due to the lack of smooth. calcification this specimen has not been Female gonopores longitudinally oval; used as holotype. The only available female opening vertical. also features a soft-shell, and although basic First pleopod of male long, slender, characteristics match the description of the bending and slightly curved distally. Two species, it was not designated as type ma­ rows of small spines on the shaft; two series terial either. The bathymetric range of B. of 3 and 5 much longer distal spines on furcata is rather wide; the holotype was each side of the fold, close to the apex; a taken in trawl between 55 and 80 m, while strong, spine-like subterminal process, and the rest of the material was obtained in a a terminal, hook-shaped shorter process; a single trawl from a depth of 566-644 m. cluster of spines on the side opposite to the fold; an obscure third lobe, covered with Discussion tiny spines, in front of the hooked process. Ethymology.—The name of the species Like several other genera included in the refers to the peculiar arrangement of the Goneplacidae or "Goneplacid-like" group subapical setae of the male first pleopod, (i.e., Pseudorhombila, Nanoplax, Oediplax, simulating a fork (furca). and Chacellus), Bathyrhombila represents a Remarks.—The smaller male features primitive evolutionary step towards a ca- more marked heterochely, the right claw tometopous stage, in which an uncovered being about 1.34 times the maximum height expanded stemite 8 unites to stemite 7. In VOLUME 111, NUMBER 3 639

Fig. 2. Holotype male, CW 24.6 mm, CL 17.5 mm (SIO C-2116). A, dorsal view of carapace; B, dorsal view of abdomen and sternal plates 7-8; C, right (upper) (SIO C-2116) and left (lower) claws, frontal view.

the former four genera, the abdominal so­ Tavares (1996: 420) note that the size of mite 2 is: notably reduced, its lateral margin vissible portion of stemite 8 varies among straight and clearly separated from the coxa specimens of a same species; data related of P5 (e.g., Oediplax granulata Rathbun, to other genera, however, are lacking. Pseu- 1893, type species of the genus; Pseudo- dorhombila, Nanoplax and Oediplax are rhombila xanthiformis Garth, 1940; P. oc- considered by Guinot (1969b, 1970) as po­ todentata Rathbun, 1906); reduced but an- tential members of a series of "Goneplaci- tero-laterally acute, in such a way that the dae" related to the Xanthidae, equivalent to acute corner is close to the coxa of P5 (e.g., the Pseudorhombilinae Alcock, 1900. Chacellus pacificus Hendrickx, 1989a); or Among the species of Pseudorhombila, the antero-laterally acute and touching the coxa abdomen-sternum organization itself varies of P5 (e.g., Nanoplax xanthiformis A. from a primitive step (sternites 7 and 8 ap­ Milne Edwards, 1880). In all cases, somite pear not in contact in ventral view, male 2 leaves a reduced portion of stemite 8 vis­ opening coxal: P. xanthiformis) to a more ible at the basis of coxa of pereiopod 5. In advanced phase [sternites 7-8 in contact on Bathyrhombila the antero-laterally pro­ a short distance, in ventral view, displace­ duced corner of somite 2 is almost in con­ ment of the male opening towards a sternal tact with the coxa of P5. In his study of position: P. quadridentata (Latreille, 1828), Bathyplax typhlus oculiferus Miers, 1886, P. octodentata (Rathbun, 1906), and P. 640 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

Fig. 3. Microphotographs (SEM) of male first gonopod (Pll). A, B and E, F, paratype, male, CW 22.8 mm, CL 16.35 mm (LACMNH 68-464.1), slightly damaged, station MV68-I-59, Gulf of California, north of Angel de la Guarda Island (29°4rN-l 13°56'W), Baja California, Mexico, detail of extremity; C, D, holotype, male, CW 24.6 mm, CL 17.5 mm (SIO C-2116) distal portion (SEM photographs) (scale: A, F, lOOX; B, E, 72X; C, D, 25X). ometlanti Vazquez-Bader & Gracia, 1995]; Guinot (1969a, b) is distinguishable in all this would make Pseudorhombila the most the above mentioned genera (in particular advanced genus of all. considering the shape of the cheliped) and The "facies goneplacien" referred to by the pterygostomian ridge, also referred to VOLUME NUMBER 3 M

by Guinot (1969a, 242) as a '*. . . caractere on the Pll of B. furcata) are also observed assez constant [in Goneplacidae], rarement on Pll of species of Pseudorhombila and signale . . ." [a rather constant feature, rare­ on the type-species of Nanoplax [i.e., N. ly reported], is also present in all four gen­ xanthiforfnis (A. Milne Edwards, 1880)] era (strong and sharp in Oediplax; strong (Hendrickx 1995), with a single cluster of and granulated in Bathyrhombila: strong to subterminal spines in the later. moderate in Pseudorhombila: weak in Cha- Another genus close to the "Pseudo- celhis). In the case of B. furcata, the general rhombilid" organization is Euphrosynoplax aspect of the crab relates it to species of Guinot. The visible portion of sternite 8, Pseudorhombila; the carapace is similar, however, is smaller in E. clausa (the type- notably wider than long, with distinguish­ species of the genus) than in Pseudorhom­ able regions and convex in lateral view. bila, Bathyrhombila and Oediplax; and is Both genera feature large to very large similar in size to sternite 8 of Nanoplax {Bathyrhombila), heavy chelipeds, although xanthiformis and the two known species of the heterochely is more marked in Pseu­ Chacelus. dorhombila. Orbits and eyes are small. When all these species are compared, Structure of the frontal and antennular they present striking similarities as far as regions and of the bucal frame is similar, as their general shape and aspect is concerned. is the shape of the third maxilliped, al­ On the basis of these considerations, and though the antero-lateral angle of the merus following the suggestion of Guinot (1970; is not so produced in Bathyrhombila (in this 1080), the use of the family-group name respect, closer to Oediplax). Both genera Pseudorhombilidae Alcock, 1900, is pro­ also feature long {Pseudorhombila) to very posed for those genera of "goneplacid-xan- long {Bathyrhombila), flattened, slender thid" crabs. P2-P5. Bathyrhombila, however, differs from Pseudorhombila in the following Pseudorhombilidae Alcock, 1900 characters: the exorbital and second teeth of Pseudorhombilinae Alcock, 1900:286, 292, carapace are fused, forming a wide, almost 297, pro parte. straight slightly projecting margin (exorbi­ Pseudorhombilinae.—Guinot, 1969b:706; tal tooth almost wanting in Pseudorhombi­ 1971:1080. la); the pterygostomian ridge, in front of the cheliped articulation, is much stronger Type genus.—Pseudorhombila. in Bathyrhombila; the second abdominal Included genera.—Bathyrhombila new segment is wider in Bathyrhombila; and the genus, Chacellus, Euphrosynoplax, Nano­ structure of the male Pll is strikingly dif­ plax, Oediplax, and Pseudorhombila. ferent (Fig. 3). Considering the shape of the Definition.—Carapace xanthoid, wider male gonopods, the slender Pll of Bathy­ than long, with 3-5 (including outer orbital) rhombila is closer to Pll of Chacellus antero-lateral teeth. Bucal frame widening {Pseudorhombila and Oediplax possess a anteriorly. Orbits of moderate or reduced shorter, more massive Pll). Ornamentation size, oval. Chelipeds goneplacids, long, of the tip of Pll however, shows affinities heavy, with long, strongly to moderately in­ with some species of Panopeidae Ortmann, curving fingers. Pterygostomian ridge (in 1893 such as Lophopanopeus frontalis front of chelipeds) strong to moderate. Ab­ Rathbun (see Martin & Abele 1986: fig. dominal somites 3-5 at least partially fused, IN). Although the "third" lobe (typical of sutures usually visible. Second abdominal Panopeidae) in Bathyrhombila furcata, new somite reduced, its antero-lateral margin in species is hardly distinguishable, the other contact with (anterior angle produced) or two processes are strongly developed. In separated (margin straight) from basis of contrast, long subterminal spines (present coxa of P5. Sternal plate wide and slightly S42 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

to moderately depressed between PI (min­ Provisional key to genera of imum width between PI equal to 0.60-0.63 Pseudorhombilidae times maximum width between P2). A small to relatively large piece of stemite 8 1. Distance between outer orbital and first anterolateral teeth much shorter than or­ visible ventrally; stemite 8 not touching bit width; these tooth partially-fused, stemite 7 in ventral view (Pll coxal) or in separated by a shallow notch. Extremity contact over a short distance (Pll displaced of male Pll with a strong longitudinally towards a stemal position). Pll long and projecting flange Nanoplax slender or moderately long and strong; or­ - Distance between outer orbital and first namentation variable. P12 short, strongly or anterolateral teeth about equal to orbit moderately sigmoid. width 2 Genera.—The family is divided into 2. Pll of male long, very slender and ta­ three groups of genera. Group A includes pering, with only a few minute spines the most primitive catometopous forms along the shaft Chacelus (i.e., Nanopla.x, Chacellus, Bathyrhombila - Pll of male stout, strong, twisted, with median to large spines along the shaft and Euphrosynoplax)\ group B includes and distal part 3 species with a larger visible piece of ster- 3. Outer orbital and first anterolateral teeth nite 8 {Pseiidorhombila pro parte and Oed- coalesced, forming an almost straight iplax)\ group C includes species with a larg­ slightly projecting margin. Extremity of er visible piece of stemite 8 in contact over male Pll with two longitudinal series of a short distance with sternite 7 {Pseudo- very long spines Bathyrhombila rhombila pro parte). - Outer orbital and first anterolateral teeth Remarks.—Among the Pseudorhombili­ reduced, separated by a granulated dae, several species present a subtriangular space; granules coarse to minute 4 hiatus between the ischium and the merus 4. Merus of MXP3 not produced antero-lat- of the third maxilliped (e.g., Chacellus pa- erally Oediplax - Merus of third maxilliped strongly pro­ cificiis; both species of Euphrosynoplax\ duced antero-laterally 5 Oediplax granulata; Pseiidorhombila xan- 5. Extremity of male Pll with a strong sub- thiformis, P. quadridentata and P. guinotae terminal or lateral upturned flange; a Hernandez-Aguilera, 1982) while other spe­ patch of strong spines just below the cies (e.g., Chacellus filiformis Guinot, flange and series of weaker spines along 1969b; Pseiidorhombila ometlanti) possess shaft Pseudorhombila an anteriorly expanded lobe at the inner an­ - Extremity of male Pll with a lateral gle of the ischium that makes contact with flange; no patch of strong subterminal the proximal margin of the merus (Hen- spines below the flange, but a series of drickx 1989a: table 1). The third maxilliped moderate size spines along the shaft . . . of other species have not been illustrated in Eiiphrosynoplax the literature and specimens have not been available for examination. In Nanoplax, the Relationships between Pseudorhombili­ partially-fused outerorbital and second teeth dae Alcock and the Panopeidae Ortmann are much narrower than in any other genus are difficult to establish. As emphasized by included in the Pseudorhombilidae, al­ Guinot (1969a:249, 250, and in lit.) this is though still separated by a shallow notch. due basically to the complexity of the Pan­ The carapace of species of Pseudorhombila opeidae sensu lato, of which a first group and Oediplax features a reduced to uncon- presents a xanthid facies and coxal male spicuous first anterolateral tooth and the opening (e.g., Eurypanopeus, Panopeus), fifth tooth varies from well (e.g., P. octo- while a second group presents a goneplacid dentata) to poorly developed (or obsolete) facies and coxal or coxo-sternal male open­ (e.g., P. quadridentata). ing (e.g., Cyrtoplax, Glyptoplax). Some VOLUME 111. NUMBER 3 ^4;^

species of the Panopeinae second group Grapsoidea.—.lournal ol the Asiatic Soeici\ oi (e.g., Glyptopla.x piignax Smith. 1870, the Bengal 6^. 2(."M:27g-45(r Balss. H. 195". Decapoda. //; Dr. H. U.. Bronnv Klas- type species of the genus, and G. consagae sen und Ordnungen des Tierreichs.—Fimtier Hendrickx, 1989b) present a sternum-ab­ Band. I. .-Xbteilung. 7. Bueh. 12. Lief: l.->05- domen organization more advanced to­ 1672. wards a catometopous organization, with Garth. J. S. 1940. Some new species o\ biaeh\uran uncovered section of sternites seven and crabs from Mexico and Central and South .•\merican mainland.—.Allan Hancc>ck Pacific eight widely in contact and covering a E.xpeditions 5(3):51-12". groove through which the penis passes (see Guinot. D. 1967. Recherches prcMiminaires sur les Hendrickx 1989b: 653). All members of the groupements naturels che/ les Crusiaces Deca- Panopeidae, including Glyptopla.x, howev­ podes Brachyoures. Les anciens genres Micro- er, feature the typical "Panopeid" Pll or­ pcuiope Slimpson et McdiU'iis Dana.—Bulletin namentation. du Museum National d"Histoire Naturelle. 2e Ser. 39(2):345-374. Specimens of the monospecific genera . 1969a. Recherches preliminaires sur les grou­ Thalassoplax Guinot and Robertsella Guin- pements naturels chez les Crustaces Decapodes ot were not available during this study. Brachyoures. VIL Les Goneplacidae.—Bulletin Both genera were briefly described by du Museum National d'Histoire Naturelle, 2e. Guinot (1969b) to accomodate specimens Sen 41(1):241-265. . 1969b. Recherches preliminaires sur les grou­ erroneously identified by Rathbun (1918) as pements naturels chez les Crustaces Decapodes Pilumnoplax elata (A. Milne Edwards, Brachyoures. VIL Les Goneplacidae (suite et 1880). Both genera are very similar primi­ tin).—Bulletin du .Museum National d'Histoire tive catometopous and feature distinctive Naturelle. 2e. Sen 41(3):688-724. male Pll. Shape of carapace (see Guinot . 1970. Recherches preliminaires sur les grou­ 1969: plate V) of both genera is apparently pements naturels chez les crustaces brach\- oures. VIIL Synthese et bibliographie.—Bulle­ different from typical pseudorhombilids tin du Museum National d'Histoire Naturelle. (carapace more squarish; wider front and Paris. 2e. Sen 5:1063-1090. orbits). Further studies will be needed to . 1977. Donnees nou\elles sur la morphologie. show if these two genera belong to the la phylogenese et la ta.xonomie des Crusiaces Pseudorhombilidae or not. Decapodes Brach\oures. These de Doctoral d'Elat es Sciences, souienue le 21 juin 1977 a Acknowledgments I'Universite Pierre-et-Marie-Curie. 2 vol. in fol.. p. I-XV. 1-486. XVI-XXIV. 56 feuilles n.n.. 78 The author thanks W. Newman and L. Fig.. 31 pi.. 2 Fig. n.n.. 14 tabl. Spencer, Scripps Institution of Oceanogra­ . 1978. Principes d'une classilication evolutive phy, for the loan of the specimens. Com­ des Crustaces Decapodes Brachyoures.—Bul­ letin Biologique de la France et de la Belgique ments and suggestions provided by D. 1 12(3):21 1-292. Guinot, T. Tavares and R. Lemaitre greatly . 1979. Donnees nou\elles sur la morphologie, helped to improve the manuscript. A. Es- la phylogenese et la taxonomie des Crustaces parza-Haro helped with some of the figures. Decapodes Brachyoures.—.Memoires du Mu­ M. Cordero edited final version of the seum National d'Histoire Naturelle, Paris. Sen manuscript. SEM Figure 3 C, D were pre­ A. Zoologie 1 12:1-354. Hendrickx. M. E. 1989a. CIUICCIIHS pacificus, new spe­ pared and taken at Scripps Institution of cies (Crustacea: Decapoda: Brachyura: Gone­ Oceanography and are courtesy of C. Gra­ placidae) from the continental shelf of the Gulf ham; Figure 3A, B, E, F were prepared and of California. Mexico.—Bulletin du Museum taken at the Institut Royal des Sciences Na- .National d'Histoire Naturelle. Paris. Sen 4. 11, turelles de Belgique by F. Fiersand J. Cillis. A(l): 191-200. . 1989b. Glyptopla.x consai>ae new species Literature Cited (Crustacea: Decapoda: Brachyura: Panopeidae) from the Gulf of California. .Mexico, with some Alcock. A. 1900. Materials for a Carcinological fauna notes on the distribution of G. pui^nax Smith. oi India. No. 6. The Brachyura Catametopa of 1870.—Bulletin du .Museum National 644 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF W ASHINGTON

d'Histoire Naturellc. Pans. Sen 4. 11. A(3); Serene. R. 19S4. Crustaces Decapodes Braclnouics dc (-,4*->-657. rOcean Indien Occidental el dc la Mci' Rou«_:c. -. 1995. Reslituiion de PscudorhomhiUi xaiulu- Xanthoidea: Xanihidae ei Trape/iidac. .\\cc un fonnis Garlh. 1940. pour Nanopla.x i>anhi Guin- addendum par Crosnier (A.): Carpiliidac ci ot, 1969 (Decapoda: Goneplacidae).—Crusta- Menippidae.—Faune Tropicale XXI\": 1-400. ceana 68(1): 12-20. Rathbun. M. J. 1893. Descriptions o\ new genera and Hernande/.-Aguilera. J. L. 1982. PscmJorhonihila i^uin- species of crabs trom the west ci">asi ot NiMih ohic. un nuevo crustaceo (Decapoda. Gonepla­ America and the Sandv\ ich Islands. //; Scieniilic cidae) en la cosla Este de Mexico.—Invesiiga- results o\' explorations b\ the L'.S. I-ish. Com­ ciones Oceanograticas/Biologia 1(4):1-16. mission Steamer "Albatross"". No. XXIV— Latreille. P. A. 1828. Tourlouroux. Encyclopedic meth- Proceedings oi' the United Slates National Mu­ odique: hisloire naturelle. enlomologie. ou his- seum 16(933 ):223-260. loire naturellc des Crustaces. des Arachnides. el . 1906. Description of a nev\ crab frcMii Diim- des Insectes. Paris 10:345-832. inica. West Indies.—Proceedings of the Biolog­ Martin. J. W.. & L. G. Abele. 1986. Notes on male ical Society of Washington 19:91. pleopod morphology in the brachyuran crab . 1893. The grapsoid crabs of America.—Bul­ family Panopeidae Ortmann. 1893, sensu Guin- letin of the United States National Museum 97; ot (1978) (Decapoda).—Crustaceana 50(2): 1-461. 182-198. Snfith, S. I. 1870. Notes on American Cruslacea. No. Miers. E. J. 1886. Report on the Brachyura collected 1. Ocypodoidea.—Transactions of the Connect­ by H.M.S. Challenger during the years 1873- icut Academy of Arts and Science 2:1 13-176. 76. //; Report Scientific Research Voyage Ta\'ares. M. 1996. Sur la \alidite de Bathypla.x lyphius H.M.S. Challeni>er. Zoology part 49. 17. Lon­ oculiferus Miers. 1886 (Decapoda. Brachy­ don. Edinburgh and Dublin. 1. 362 pp. ura).—Crustaceana 69(3):413-423. Milne-Edwards. A. 1873-1881. Etudes sur les Xip- Vazquez-Bader. A. R.. & A. Gracia. 1991. Eaphrosx- hosures ct les Crustaces de la region mexicaine. noplax campechiensis. new species (Crustacea. //; Mission scientifique au Mexique et dans Decapoda. Brachyura. Goneplacidae) from the LAmerique Centrale. Rech. Zool. Faune Ame- continental shelf of southwestern Gulf of Mex­ rique Centrale et Mexique. part 5. vol. I. Paris. ico.—Bulletin du Museum National d"Histoire Imprimerie Nationale. 368 p. Naturelle. Paris. 4e. Ser. 13(3-4):433-438. Milne-Edwards. H. 1937. Histoire naturelle des Crus­ taces. comprenant Lanatomie, la physiologic et . & . 1995. A new crab species of the la classification de ces animaux. Paris II, 532 genus PseudorhomhiUi H. Milne-Edwards. 1837 pp. (Crustacea: Decapoda: Goneplacidae).—Pro­ Ortmann. A. 1893. Die Dekapoden-Krebse des Strass- ceedings of the Biological Society of Washing­ burger Museums. VII. Theil. Abtheilung: ton 108(2):254-265. Brchyura (Brachyura genuina Boas) II. Unter- Williams. A. B. 1984. Shrimps, lobsters and crabs of abthcilung : Cancroidea. 2. Section :Cancrinea. the Atlantic coast of the Eastern United States. 1. Gruppe : Cyclometopa.—Zoologische Jahr- Maine to Florida. Smithsonian Institution Press. bucher 7:411-495. 550 pp.