Boone, Crustacea, Cruises of ''Eagle" and " Ara," 1921-23 51 



margin, the second of which is very large; another spine is just be- 

 hind this in the depression formed by the cervical groove; the 

 branchial region has eight such spines on its lateral and postlateral 

 margins, and there is a submedian pair on the intestinal margin, 

 making a total of thirteen spines on each half of the carapace mar- 

 gin, besides which there are one or two secondary spines between the 

 large spines of the branchial margin. The entire dorsal surface is very 

 rough and uneven. The cervical groove is deep, and there is a pro- 

 nounced depression between the hepatic and branchial regions, which 

 is continuous posteriorly with the strong urogastric depression; the 

 cardiac region is lightly circumscribed. The entire dorsal surface is 

 rough, with small spinous granules of irregular size and position 

 interspersed among the larger spines which ornament it. There is 

 a median longitudinal row of spinous granules extending from the 

 posterior half of the rostrum to down the gastric region. There is 

 also a submedian pair of spines on the anterior gastric region, just 

 behind which there is an arcuate transverse line of seven or eight 

 spinules, behind which there is a submedian pair of spinules. There 

 are two submedian pairs of small spines, one behind the other, on the 

 cardiac region; there are five or six conical spines placed irregularly 

 on the summit of the branchial region. The pterygostomian region 

 and lateral wall are also very roughly granulose. 



The abdomen is large, asymmetrical, with the proximal joint nearly 

 half an inch long and armed with a pair of large, conical, submedian 

 tubercles near its anterior margin ; there is a row of eight spines 

 along the posterior margin, of which the submedian pair are the 

 largest and the marginal spine the smallest ; there are two other spines 

 on the lateral margin of this segment ; the remainder of the abdomen 

 is composed of closely placed asymmetrical plates, which are rough- 

 ened with blunt tubercles. 



The eyestalk is small, normally directed obliquely outward, the cor- 

 nea spherical, terminal, shining black. 



The inner antennae have the proximal article short, the second and 

 third articles clavate, the flagellum very short, hirsute, its extended 

 tip reaching as far forward as the rostral tip. 



The external antennae have the peduncular joints about as long as 

 those of the antennulae; the acicule is represented by an acuminate, 

 spine-like blade which reaches as far forward as the distal margin of 

 the second pedunculate joint ; the flagellum extends as far forward as 

 the base of the propodus of the extended chelipeds. 



