PART 1 GARTH : PACIFIC OXYRHYNCHA 99 



Type: Male cotype, M.C.Z. No. 1247, length 11.4 mm (not 10.7 



mm if 1 in = 25.4 mm), width 8.1 mm. 



Type locality: Panama, Rev. J. Rowell, collector. 



Pacific localities subsequently reported, with collectors: Mexico: 

 Lower California: Magdalena Bay, C. R. Orcutt (Rathbun) ; Gulf 

 of California: Santa Inez Bay, 29 fathoms, Zaca (Crane); Bay of 

 Panama: Panama, Sternbergh (Rathbun) ; Colombia: Malaga Bay, 2-5 

 fathoms, Askoy (Garth). Atlantic records omitted as being doubtfully 

 of this species (See remarks below). 



Atlantic analogue: Inachoides forceps A. Milne Edwards (See Re- 

 marks below). 



Diagnosis: Carapace smooth and bare, no tubercles on gastric or 

 dorsal portion of branchial regions and only a few granules on lateral 

 margins; a single cardiac tubercle. Postorbital spine inconspicuous, 

 antennal spines divergent. Antennular fossae dorsally discernible as two 

 translucent oval patches. Pollex of male chela bent at middle, a strong 

 basal tooth. Tip of male first pleopod sharply triangular. Size small. 



Description: Carapace mostly smooth, and covered with a soft 

 pubescence easily removed. Gastric and branchial regions protuberant, 

 rounded, glabrous; cardiac with a single median tubercle; hepatic conical, 

 armed at the apex with a short, deflexed spine. Rostrum rather long, 

 with a styliform extremity as long as the thicker, tapering basal half. 

 Postocular spine very small, blunt. . . . Two or three tubercles on the 

 inferolateral regions in front of the bases of the chelipeds. Outer maxil- 

 lipeds with a sharp longitudinal denticulated ridge on the ischium; 

 anterointerior corner of the [merus] sharply projecting forwards. 

 Dactyli of the posterior three pairs of [legs] falciform, equal. (Stimpson) 



Basal antennal article traversed by an oblique ridge, minutely 

 denticulate; stout anteroexternal spine exposed to dorsal view. 



Chelipeds of male massive ; merus long, cylindrical, with a spinulous 

 inner surface; carpus also spinulous internally; palm stout, widest at 

 middle, inner surface spinulous and noticeably more convex than smooth 

 outer surface, spinules irregularly arranged except along inferior border, 

 there forming a row; fingers equally curving, a large tooth at base of 

 deflexed pollex, narrow gape occupied by comblike bristles to which 

 particles of mud adhere. 



First pair of walking legs longer and more slender than remaining 

 pairs, dactyli straighter ; last three pairs of legs subequal in length, dactyli 

 nearly as long as the respective propodi and curving. 



