PART 1 GARTH : PACIFIC OXYRHYNCHA 53 



slender, reaching beyond postorbital spine by nearly half their length. 

 First movable segment of antenna longer than broad, outer angle not 

 produced. Fingers of adult male gaping, one tooth in gape. Male pleopod 

 with a large triangular lateral projection. 



Description: Carapace broadly rounded posteriorly, narrowing to 

 base of orbits anteriorly, hairy, and tuberculate on raised portions only. 

 Cardiac area with three larger tubercles in a backward-pointing triangle, 

 a rectangular tubercle leading to the gastric region. Gastric region high, 

 straight-sided, and surmounted by a transverse row of five tubercles, 

 the median most advanced. Branchial regions swollen, tuberculate, a 

 sharp spine directed laterally and upwardly at each posterolateral angle ; 

 in front of this and well within the lateral margins an irregular line 

 of sharpened tubercles leading forward to the base of the postorbital 

 spine, interrupted slightly by the shallow groove delimiting the hepatic 

 from the branchial area. A rectangular tubercle half way between each 

 posterolateral spine and the tuberculate intestinal region. In addition 

 to the principal tuberculations mentioned, scattered tubercles and masses 

 of hooked hairs occurring on all elevated regions, the depressions between 

 them being largely smooth and bare. Rostral horns acute, straight 

 margined, separated nearly to their bases, and each surmounted by a 

 double row of hooked hairs. Eyestalks long, slender, tapering abruptly 

 from bulbous bases, and extending considerably beyond the acute and 

 strongly divergent postorbital spines. Basal antennal segment broad, a 

 sharp tooth at its anteroexternal angle; first free segment narrowly 

 rectangular, about twice as long as broad, falling short of the tip of the 

 rostrum, and heavily fringed with long hairs along its outer margin. 

 Merus of third maxilliped triangular, deeply notched for the insertion 

 of the palpus, anteroexternal angle acute, prominent. 



Chelipeds of adult male slightly longer than carapace, and slightly 

 shorter than the first ambulatory legs. Merus of chelipeds massive, 

 smooth, cylindrical, a cluster of tubercles on its outer proximal margin. 

 Carpus with a prominent outer and suggested inner crest, with a shallow 

 sulcus between them. Manus high, crested, smooth, bare, and marbled, 

 tapering distally; fingers long, slender, gaping in an elongate oval, 

 movable finger with a broad tooth near its base, immovable finger 

 slightly deflexed, one sharp tooth opposite digital tooth and one or more 

 smaller teeth nearer the tip, fingers meeting at extremities only. 



Ambulatory legs diminishing regularly in length from first to last, 

 densely clothed with clavate hairs interspersed with long fine hairs, a 



