PART 1 GARTH : PACIFIC OXYRHYNCHA 303 



small, blunt, or tuberculiform ; but the anterior ones larger, and, like the 

 spines on the legs, abruptly bent at the tip, having a truncated appear- 

 ance, with the sharp apex pointing forward. A similar spine and two 

 smaller ones on the subhepatic region ; the oblique ridge separating the 

 pterygostomian from the subhepatic region armed with five spines, the 

 anterior three being small and toothlike. Horns of the rostrum rather 

 large and divergent, forming considerably more than half the length of 

 the rostrum, and with their tips as well as those of the antennai spines 

 bent inward. All of the spines much more acute in young specimens than 

 in adults. 



Chelipeds long, the merus armed with numerous (about 13) blunt 

 spines on the outer side; the carpus tuberculated above; the large and 

 compressed hand perfectly smooth, and unarmed above and below; the 

 fingers less than half as long as the palm, and gaping; and the dactylus 

 bearing a strong truncated tooth at the middle. Merus of the ambulatory 

 [legs] armed with seven to ten spines along the upper edge, and two or 

 three below near the extremity; the carpus slightly tuberculated, and the 

 [propodus] unarmed. 



The adult male specimens entirely naked, but young and female 

 specimens frequently pubescent. (Stimpson, 1871a, modified) 



Supplementary description (based on a 21.6 mm male from San 

 Esteban Island) : Basal antennai article armed with three strong margi- 

 nal spines including the anteroexternal ; this spine larger and more 

 anteriorly directed than the other two; first free antennai segment 

 reaching nearly to tip of rostrum. (See text-fig. 8A) 



Merus of external maxilliped slightly concave from side to side, 

 anterointernal angle produced as a narrow, rounded lobe with a smooth 

 margin, anteroexternal angle a broad, rounded lobe with a spinulous 

 margin; an isolated, erect spinule just external to insertion of palpus. 

 (See text-fig. 8B) 



Male abdomen with seven free somites ; widest at middle of somite 

 three, narrowing gradually to base of somite six, then flaring slightly; 

 somite seven triangular, tip rounded. Male first pleopod cylindrical, 

 tapering, tip acute, recurving, a setiferous fold on concave margin. (See 

 Plate S, fig. 1) 



Carpus of cheliped spinulous, not smooth as shown by A. Milne 

 Edwards (1875, pi. 18, fig. 3). In spite of its large size, the specimen 

 shows only an incipient digital tooth. 



