150 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 18 



Description: Chelipeds dissimilar and unequal, the right much 

 larger; merus short, compressed, with narrow longitudinal ridge on 

 superior surface ; carpus short, also crested with narrow ridge ending in 

 sharp projection just short of distal margin, inner margin bearing for- 

 ward hooked spine medially and similar larger spine at anterior end, 

 overhanging distal margin ; hand suboval, twice as long as carpus, oper- 

 cular face completely bordered by sharp teeth separated by rounded 

 sinuses and with unevenly spaced angular elevations. 



Minor cheliped very small, less than one third the width of major 

 hand; carpus with forward hooked spine medially on inner margin and 

 two prominent spines side by side at anteromedial corner; hand with 

 inner margin marked by minute sharp, forward inclined spines; fingers 

 about as long as palm, setose, not gaping at base. 



Precervical portion of carapace about as broad as long, rugose, slight- 

 ly setose ; median point triangular, acute, much in advance of very acute 

 lateral points ; postcervical portion membranous, slightly setose on cardiac 

 and intestinal areas. 



Eyestalks cylindrical, long, slender, much constricted in middle, 

 cornea elongate, only slightly dilated; ophthalmic scales short, with 

 rounded margins and prominent, acute, subterminal spine. 



Antennal acicle slender, outward-curving, acute, falling short of 

 corneal base; peduncle when extended slightly longer than eye; flagellum 

 with long scattered setae. 



Ambulatory legs about equally developed on both sides, superior and 

 inferior margins hairy, unarmed except for claw-tipped dactyli which 

 are spinulose on inferior margins. 



Fourth pair of thoracic legs extremely short, subchelate, rasp re- 

 stricted to terminal margin of propodus; fifth pair minutely chelate, 

 rasp covering both fingers and laterally swollen propodus. 



Abdomen longer than thorax, membranous, caudal shield well calci- 

 fied ; anterior tergum transversely convex, bearing tufts of setae, antero- 

 lateral corners rounded off, posterolateral corners produced slightly into 

 small triangular points, suture deep and flexible; posterior tergum 

 smaller, bearing tufts of long setae on posterolateral corners and two 

 smaller tufts on terminal margin. 



Telson symmetrical, a simple calcareous plate, with smoothly rounded 

 corners and entire margins; uropods symmetrical, heavily calcified. 



Distribution: Previously recorded from Cape San Lucas in the 

 Gulf of California (Benedict), and a single specimen from Arena Bank, 

 Gulf of California, in 50 fathoms (Glassell). 



