320 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



ternal maxilliped narrower than ischium and tapering distally. Male 

 cheliped no more robust than walking legs. Tip of male first pleopod 

 falciform, grooved, and opposed by an erect, setiferous blade or keel. 

 Description: Carapace circular, covered as well as the legs, with the 

 exception of the fingers and the dactyli, with a short close tomentum and 

 some tubercles. On the branchial region three tubercles, placed on an 

 oblique line, the foremost very small and scarcely visible through the fur, 

 the second better developed and the third much stronger and sharper; 

 the gastric region bearing two tubercles, the foremost small again and 

 scarcely visible, the second better developed ; the cardiac region bearing 

 a tubercle of about the same height. Anterolateral margin armed with 

 three tubercles, the anterior [one] small, the others much better devel- 

 oped, more spinelike. 



Rostrum exceedingly short and hardly breaking the general outline 

 of the front, formed by a single rather broad spine. Eyes small ; the upper 

 outer- and lower innerorbital angle tuberculiform, the latter formed by 

 the basal antennal article. The next two antennal articles swollen and 

 the proximal of the two broadened distally. The flagellum rather long 

 and slender. Pterygostomian region longitudinally grooved, the upper 

 outer angle of this groove marked by a strong spine. Both inner and outer 

 margin fringed by long hairs; those on the inner margin implanted on 

 the exognath and on the outer part of the merus and the ischium of the 

 outer maxillipeds. The form of the merus of the outer maxilliped rather 

 obscured by these hairs; but when denuded, the merus less broad than 

 the ischium and tapering distally. 



Chelipeds slender, about as long as the equally slender walking legs 

 of the last pair; the other walking legs missing [in the lectotype]. 



Abdomen seven-segmented. 



In the two young specimens all the protuberances of the cephalo- 

 thorax are exceedingly long and spinelike; the branchial region bears 

 two of these spines, while anteriorly of the two gastric spines a third 

 but lower one can be observed. (Buitendijk, modified) 



Female resembling male in all particulars ; cheliped even more feeble. 

 Female abdomen with a strong spine on segment 2, a lesser spine on 

 segment 3, and a low tubercle on each succeeding segment except the last. 



Material examined: In addition to the male lectotype in the Leiden 

 Museum, the following specimens from Allan Hancock expeditions: 

 Chacahua Bay, Oaxaca, Mexico, 5-10 fathoms, January 9, 1938, Velero 

 III station 765-38, one male; off San Jose Light, Guatemala, 7-11 

 fathoms, January 11, 1938, Velero III station 770-38, two males, one 

 ovigerous female (paratype), and five young. 



