134 BULLETIN 97, UNITED dTATES NATIONAL MUSEUM. 



segments fused, last segment subtriangular, widest, and laterally 

 angled not far from sixth segment. 



Sexual variation. — Female somewhat larger and more swollen than 

 male, frontal region more inclined, posterior margin wider, and 

 wider than in female transversalis ; fingers elongate and very slightly 

 gaping, less slender than in female transversalis. 



Measurements. — Male holotype, length of carapace 5.G, width of 

 same 11 mm. Female (TG39), length of carapace G.l, width of same 

 13.3 mm. 



Range. — Trinidad (off Venezuela) and Monos Island, off NW. 

 coast of Trinidad. 



Material examined. — Trinidad; shore; Jan. 30-Feb. 2, 1884; 

 steamer Alhati^oss; 1 males (1 is holotype), 7 females (2 ovig.) 

 (7G39). Monos Island, Trinidad; shore; Jan. 30-Feb. 2, 1884; 

 steamer Albatross; 1 male (2313G). 



PINNIXA CRISTATA Rathbun. 

 Plate 29, figs. 8 and 9. 



Pinnixa cristata IIathisun, Amer. JSat., vol. 34, 1900, p. 589 (type-locality, 

 Beaufort, North Curoliiia; holotype female, Cat. No. 42817, U.S.N.M.). 



Diagnosis. — Sharp crest across posterior part of carapace. Fingers 

 gaping, thmnb short. Legs narrow; dactyls slightl}^ curved except 

 last pair. 



Description of female. — Carapace very short, narrowed at either 

 side; a high, sharp, transverse crest across carapace, ending above 

 bases of last legs; surface punctate, wrinkled, and microscopically 



granulate; deep furrow behind gastric 

 region; antero-lateral margin a raised crest, 

 stopping short of hepatic region; posterior 

 margin wide, concave. Front deflexed, not 

 advanced ; orbit no Avider than half of front. 

 Chelipeds rather stout; palm suboblong, 

 Fig. ts.-pTn-nixa cristata, ^^^^h upper and lower margins convex, sur- 

 oLTEit MAxiLLii-ED OF FE- facc covcrcd wltli a reticulate pattern of 

 MALE noLOiirE, X o. ^^^ granulations; thumb short, subtriangu- 

 lar, deflexed ; a subbasal tooth on prehensile edge, also a small tooth 

 near the tip, forming a truncate extremity against which the tip of 

 the gaping dactylus fits; inner margin of dactylus bent in a right 

 angle at middle, subentire. 



Dact3'li of legs slender, of fourth leg straight, of first, second, and 

 third slightly curved; first leg slender, reaching to end of propodus 

 of second ; second intermediate in width between first and third, reach- 

 ing one-third length of dactylus of third; merus of third leg 2| 



