PART 1 GARTH : PACIFIC OXYRHYNCHA 165 



a ridge of prominent granulations over the posterior margin. Rostrum 

 very small, bifid, and with a small sulcus continued backwards from the 

 division. Orbits with a broad, triangular fissure above, the tooth on each 

 side flattened and triangular, the outer one the larger. Eyes not larger 

 than the peduncles; peduncles elongated, slender, projecting forwards 

 and slightly curved inwards. 



[Antennules] extremely minute, and placed far back behind the 

 rostrum. Antennae hairy, short, the basilar [article] broad and flat, 

 having a triangular external tooth extending as far forwards as that of 

 the orbit; second [article] flat, cordate, anteriorly emarginate for the 

 insertion of the third [article], also compressed and much smaller than 

 the previous one; the remaining [articles] small and cylindrical. External 

 [maxillipeds] with [exognath] gradually acuminated ; the [endognath] 

 with the [ischium] rather broad and rhomboidal; the [merus] trian- 

 gular with the anterior angles somewhat produced. 



Abdomen (in the immature female) oval, consisting of seven nearly 

 equal articulations, obtusely carinated along the center; each of them 

 delicately ciliated at its anterior margin. 



[Legs] of moderate length; the [cheliped] (in the female) consider- 

 ably smaller than the rest, slender, slightly compressed, and smooth ; hand 

 with a small obtuse tooth above and one beneath, at the base ; the fingers 

 with the margins minutely serrated. The movable finger longer than the 

 other, and curved over its extremity. The remaining pairs of [legs] 

 decreasing in length from the second to the fifth [first to fourth], de- 

 pressed, and slightly hairy; the [propodus] having a shallow sulcus on 

 each side; the [dactylus] minutely toothed beneath. (Bell, modernized 

 as to terminology) 



Material examined: 23 specimens from 11 stations. (See Table 27) 

 From Tiburon Island, Gulf of California, Mexico, via the Revilla 

 Gigedo Islands of Socorro and Clarion, to Bay of Manta, Ecuador. In 

 addition, one young female from Post Office Bay, Charles Island, Galapa- 

 gos, 4 fathoms, February 6, 1933, Velero III station 55-33, not reported 

 in Garth (1946). 



Measurements: Largest specimen, male: length 14.3 mm, width 

 including teeth 13.7 mm, without teeth 12.2 mm, rostrum 0.8 mm, width 

 1.5 mm, cheliped 15.0 mm, chela 7.2 mm, dactyl 3.0 mm, height of palm 

 2.8 mm, ambulatory legs 13.3, 12.9, 12.3, and 11.1 mm, respectively. 

 Female specimen: length 17.4 mm, width including teeth 16.5 mm. 



Color in life: Vividly white on white coral sand. (Steinbeck and 

 Ricketts) 



