THE GRAPSOID CRABS OF AMERICA. 19 



1889; station 3016, Alhatross; 2 males (1 is holotype) (174G2). Lat. 

 29° 54' 30" N.; long. 113° 01' 00'' W.; 58 fathoms; gn. M.; temp. 

 61.8° F.; Mar. 24, 1889; station 3017, Alhatross; 1 female (174C3). 



Gulf of California, off Point San Fermin; lat. 30° 21' 00" N.; 

 long. 114° 25' 15" W.; 30 fathoms; gy. M.; temp. 62° F.; Mar. 27, 

 1889; station 3035, Alhatross; 1 young female (17464). 



Genus BATHYPLAX A. Milne Edwards. 



Bathyplaa; A. Milne Edvvakds, Bull. Mus. Couip. Zool.. vol. S, ISSO, p. 16; 

 type, B. typhhi A. Rlilne Edwards. 



Carapace hexagonal; antero-lateral margins arcuate and armed, 

 postero-lateral margins converging. 



Front straight, about two-fifths width of carapace. Orbits small, 

 shallow, ill-defined; eyes small, immovable, deficient in pigment. 

 Antennae standing in the orbital hiatus; broad joint reaching the 

 downward prolongation of the front; flngellum long. Antennules 

 transverse. 



Buccal cavity widening rapidly anteriorly. Palatal ridge strong. 

 Merus of outer maxilliped much wider than the ischium, its antero- 

 external angle expanded. 



Chelipeds dissimilar. Ambulatory legs slender. 



Abdomen widest at third segment which reaches the coxae of the 

 last pair of legs ; no segments fused. 



Only one species known. 



BATHYPLAX TYPHLA A. Milne Edwards. 



Plate 2. 



Bathyplax typhlus A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, ISSO, 



p. 16 (t.vpe-lociility, Frederickst.adt, St. Croix Island. 451 fathoms; type 



in M. C. Z.). 



1886, p. 230, pi. 20, Hg. 3 (type-lo.-ality, south of Feruanibuco, 30 to 400 



fathoms; type in Brit. Mus.). 

 Bathyplax typJilus, var, oculiferuH Miebs, Challenger Kept., Zool., vol. 17, 



Diagnosis. — Orbits rudimentary; eyes immovable, almost blind. 

 Buccal cavity very wide in front. Chelipeds dissimilar ; stridulating 

 ridge on arm. 



Description. — Carapace flat transversely, convex longitudinally; 

 posteriorly uneven, the cardiac and posterior mesogastric region 

 deeply delimited. Surface pubescent and for the most part granulate. 



Fronto-orbital width about three-fifths that of the carapace. Edge 

 of front margined, bent down a little at the middle. Orbit without a 

 superior inner or outer angle; too small to hold the small spherical 

 light-brown cornea set on a short stalk; inferior inner angle denti- 

 form. Two conical distant antero-lateral spines, the first one re- 

 moved from the orbit. 



