414 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



anteroextemal angle broadly lobate, merus inserting at a point consid- 

 erably below the distal extremity of the ischium. 



First ambulatory leg much the longest in the male, the remaining 

 legs gradually diminishing; those of the female rather short; legs cylin- 

 drical, pubescent, somewhat nodose. Carpus slightly inflated and grooved 

 superiorly ; dactylus with lower borders spinulous, tip yellow and incurv- 

 ing. (Garth, 1940) 



Supplementary description: Male cheliped considerably longer than 

 carapace, including rostrum ; merus reaching middle of rostrum, bearing 

 four equidistant superior spines; carpus nodose; manus cylindrical, 

 scarcely tapering; dactylus less than one-third length of propodus, fingers 

 lightly banded at base, gaping proximally, a low tooth in gape, tips 

 evenly denticulate and slightly incurving. 



Male abdomen seven-segmented, a low setose tubercle at middle of 

 first three or four somites. Male first pleopod with keel similar to, and 

 nearly as long as, channeled tip, giving apex a distinctly bifid appear- 

 ance. (See Plate Y, fig. 4) 



The young of the species are very slender in proportion to their 

 width, the slenderness being accentuated by the elongate rostrum and 

 the produced posterior portion of the carapace. The four bosses arranged 

 in a diamond are not apparent in the smallest specimens. 



Material examined: 10 specimens from 6 stations. (See Table 87) 

 Isabel and Maria Magdalena Island, Mexico ; Port Parker, Costa Rica ; 

 and Santa Elena Bay, Ecuador. 



Measurements: Male holotype: length 28.6 mm plus 3.3 mm 

 (broken tip of rostrum), width without spines 18.6 mm, rostrum (in- 

 cluding broken tip) 9.0 mm, basal width 3.7 mm, cheliped 35.5 mm, 

 chela 15.5 mm, dactyl 5.0 mm, height of palm 2.5 mm, ambulatory legs 

 29.5, 20.8, 17.0, and 16.0 mm, respectively. Female specimen, rostrum 

 damaged: length 28.5 mm, width with spines 19.6 mm, without spines 

 16.0 mm. 



Color in life: Not recorded. 



Habitat: Dredged once on rocky bottom, once on sand and shell bot- 

 tom, and three times on coralline bottom. 



Depth: 10 to 30 fathoms. 



Size and sex: The type series, exclusive of a male and female para- 

 type sent to the U. S. National Museum unmeasured, contains young 

 from 6.4 mm, males from 9.8 to 31.9 mm, and females from 22.3 to 

 28.5 mm. 



