PART 1 GARTH : PACIFIC OXYRHYNCHA 309 



shallow cup into which the reniform cornea partially retracts. Gastric 

 region worn smooth of pubescence, bearing two low tubercles along its 

 midline, and separated from the moderately elevate and nontuberculate 

 cardiac region by a short, transverse, tuberculate ridge at the genital 

 level. Intestinal region prolonged posteriorly into a blunt triangular spine 

 or tubercle. Hepatic regions small, tumid, hirsute, bearing one spinule at 

 the level of the exorbital spine and three smaller spinules at the sub- 

 hepatic level. Branchial regions hairy, delimited anteriorly from the 

 hepatic and medially from the cardiogastric regions by shallow sulci but 

 confluent posteriorly with the intestinal region, an almost imperceptible 

 tubercle at the anterointernal angle of each. Of the scattered marginal 

 spinules three most prominent : an acute anterolateral, a midlateral, and a 

 blunt postlateral, inside of the latter a smaller spinule, not marginal. 

 A postlateral branchial fold above the rimmed posterior margin of the 

 carapace. 



Basal antennal article narrowing anteriorly to half its basal width, 

 the acute anteroexternal spine completely exposed in dorsal view, the 

 posteroexternal spine serving to define the orbit ; first two free segments 

 narrowly cylindrical, the first falling short of the tip of the rostrum; 

 flagellum long. 



Ischium of external maxilliped with inner margin serrate; merus 

 triangular, outer angle rounded, scarcely produced, inner angle a short, 

 truncate blade, between these a slight notch to receive the palpus; first 

 segment of palp tomentose, broadening distally, second segment cylindri- 

 cal, third segment tapering to extremity, all segments hairy. 



Cheliped of male with merus trigonal, inner margin irregularly spin- 

 ulous, outer margin with four larger spines, a diagonal row of sharp 

 tubercles across inferior surface; carpus crowded with sharp spinules; 

 manus inflated, smooth and bare, about five compound spinules in a 

 single row on superior proximal margin ; fingers slender, incurving, 

 gaping slightly in basal two-fifths, tips crenulate, internally excavate and 

 setigerous, a low, truncate, digital tooth. Ambulatory legs long and slen- 

 der, all segments pubescent, the meri alone bearing an anterior row of 

 stout setae in lieu of spines; first leg noticeably longest, the remaining 

 pairs decreasing regularly in size; meri narrow, but little broadened 

 medially, carpi slightly grooved, propodi greatly elongated, dactyli short, 

 tips only incurving. 



Male abdomen with seven free segments, widest opposite third, 

 diminishing in width towards the triangular seventh, the tip of seventh 

 rounded. Male first pleopod conspicuously notched at level of aperture, 



