146 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



Subfamily PRIONOPLACINJE. 



HOMOIOPLAX, new genus. 



Differs from Carcinoplax Mine Edwards * only in haying the third 

 segment of the male abdomen too narrow at its base to cover the ster- 

 num between the last pair of legs, a character which distinguishes the 

 subfamily Prionoplacinse from the Carcinoplacinse. The first seg- 

 ment and the proximal portion of the second segment of the abdomen 

 in Homoioplax do cover the sternum, as in C. longimanus. 



Type of genus. — Homoioplax Tiaswelli (Miers) = PseudorJiombila 

 Tmswelli Miers, Crust. Alert, 1884, p. 241. 



(o/iowc, similar; 7z\a£, anything flat and broad, carapace.) 



Subfamily RHIZOPIN^]. 

 CERATOPLAX FULGIDA, new species. 



Type-locality. — Near Marinduque Island: Tayabas Light (outer) 

 N. 43° W., 6 miles; lat. 13° 49' 40" N.; long. 121° 40' 15" E.; 83 

 fathoms; gn. m.; February 24, 1909; station 5371, Albatross; one 

 male type, one female. 



Type.— Cat. No. 46401, U.S.N.M. 



Dimensions. — Type male, length of carapace, 4.5 mm.; width of 

 same, 7.4 mm.; fronto-orbital distance, 4.1 mm.; front, 2.2 mm.; 

 length of third leg, 10.3 mm. 



Smooth, shining, and bare except for a few hairs on the terminal 

 half of the legs, a border on the inner edge of the merus and carpus of 

 the chelipeds, and pubescence on lower surface of carapace. The 

 carapace is anteriorly deflexed, antero-lateral margins acute, postero- 

 lateral margins blunt and converging behind, posterior margin arcu- 

 ate. Regions scarcely indicated, although there are some pit-like 

 depressions regularly placed. Front faintly bilobed, corners rounded, 

 edge sharp. The pear-shaped eyes have their upper surface sepa- 

 rated from their anterior surface by an acute edge continuous with the 

 margin of the carapace; cornea black, ventro-terminal. 



Epistome vertical, edge sharp and straight, not emarginate. Buc- 

 cal cavity broadly quadrate, filled by the maxillipeds; outer angle of 

 the merus strongly produced in a truncate tooth. 



Chelipeds nearly equal, dissimilar; wrist without an inner tooth; 

 propodus with a sharp, marginal line below; propodal finger a little 

 deflexed; fingers when closed, nearly meeting, tips crossing; middle 

 teeth of larger immovable finger prominent; teeth of smaller chela 

 lower and more acute. 



Dactyli of first three legs falciform; of last leg, bowed downward 

 and backward. 



First segment of male abdomen linear, almost imperceptible; sec- 

 ond half as long as the third and broadest distally; lateral angles of 



i Ann. Sci. Nat., ser. 3, vol. 18, 1852, p. 164 [128]. 



