PART 1 GARTH : PACIFIC OXYRHYNCHA 109 



one-third and one-fourth postrostral portion of carapace. Orbits without 

 ornamentation, their margins subparallel ; postorbital granule minute, not 

 visible in dorsal view. Gastric region swollen, two median setose tubercles 

 forming a small diamond with two lateral clusters of hooked hairs. 

 Cardiac region less prominent and with a single median tubercle. Hepatic 

 regions small, tumid, hair-tipped, a cluster of hooked hairs on their 

 anterolateral margins. Branchial regions depressed, traversed by a 

 longitudinal row of curved hairs, and flaring considerably towards the 

 bases of the ambulatory legs. 



Basal antennal article with a thickened ridge extending obliquely 

 from inner proximal to outer distal margin, first two free segments 

 cylindrical, the second overreaching rostrum by half its length. External 

 maxilliped with merus subtriangular (rather than subquadrilateral, as 

 shown in Finnegan, text-fig. 3B), anterointernal angle produced as a 

 thin blade, margins spinulous. Sternal plates not deeply separated ; 

 sternum with two setose tubercles in advance of abdomen. 



Chelipeds both finely and coarsely pubescent; merus abruptly bent, 

 carpus with a few spines or spinules ; manus moderately inflated, fingers 

 meeting with a narrow gape, gape without teeth for its basal third, teeth 

 alternating. First ambulatory leg three and one-half times length of 

 carapace, its dactylus slender, unarmed, and equal to one-third the 

 length of the propodus; dactyli of remaining legs falcate, spinulous. 

 Second, third, and fourth ambulatory legs decreasing in proportion to 

 carapace length in the ratios of 2.8, ?, and 1.6 to one. Dactyl of fourth 

 ambulatory leg nearly as long as propodus, that of the male measuring 

 2.2 mm as compared with a propodus of 3.0 mm. 



Male abdomen widest opposite second segment, narrowing rapidly 

 to base of fused sixth and seventh segments, the sides of which are sub- 

 parallel ; first segment with a single large tubercle, remaining somites 

 each with a cluster of hairs in lieu of a tubercle. 



Material examined: 18 specimens from 12 Hancock stations. (See 

 Table 16) These range from Puerto Culebra, Costa Rica, to La 

 Libertad, Ecuador, and include a male and female from the type 

 locality, Gorgona Island, Colombia. Additional material consists of a 

 male and an ovigerous female from the Askoy expedition. 



Color in life: Entire carapace and legs ecru olive with a few scarlet- 

 red blotches around cardiac region. Eyes dull reddish lavender. Ventral 

 side ecru olive with numerous tiny black dots. Maxillipeds rich orange 

 dotted with black. (Petersen, of a male from Secas Islands, Panama) 



