Boone, Crustacea, Cruise of "Alva," 1931 155 



Technical description : Carapace oval, moderately convex length- 

 wise also from side to side; greatest width not quite one and one- 

 half times the length; frontal margin equal to two-fifths of the total 

 width of carapace, moderately deflected, cut into four lobes, the inner 

 or submedian pair of which are the wider and slightly in advance of 

 the preorbital pair, from which they are separated by a rounded sulcus 

 of greater depth than the shallow median notch. The orbit is rather 

 large, elliptical, with the entire margin finely crenulated; two closed 

 sinuses on the outer half of the upper margin and with the lower mar- 

 gin partially visible in a dorsal view. The anterolateral margin is 

 much shorter than the postlateral margin, rounded and crenulate and 

 bearing four minute spines which are not much larger than the adja- 

 cent granules. The postlateral margin is slightly concave and mod- 

 erately convergent posteriorly; the posterior margin being nearly as 

 wide as the frontal margin and straight. The regions are scarcely de- 

 lineated, but the median sulcus between the frontal lobes is clearly 

 defined and there are a pair of very low rounded lobes behind the fron- 

 tal margin and between the orbits. On the epibranchial region, behind 

 and following the curvature of the anterolateral margin and extending 

 inward behind the orbit as far as the inner sinus, there is an elevated, 

 arc-like, granulated ridge that defines the anterior border of a low flat- 

 tish lobe, and behind this and more inward in position, there is a sec- 

 ond similar low lobe and ridge, the outer end of which is about oppo- 

 site the union of the antero- and posterolateral margins. Along the 

 anterolateral margin and more abundantly along the inferior orbital 

 margin each, there are a series of stiff, upstanding solitary setae. The 

 male belt is narrow, seven-segmented, with a triangulate tip. 



The chelipeds are very large in the male and definitely unequal, 

 with the merus short, closely appressed to and not extending beyond 

 the carapace ; the carpus large, convex, and covered with 18 to 20 large, 

 conical, procurved spines or rounded tubercles ; the palm is high, the 

 upper margin set with four or five large spines similar to those of the 

 carpus ; the outer face of the palm is swollen, very convex and entirely 

 covered with these large rounded or conical tubercles, which for the 

 greater part are set regularly in longitudinal series in about eight 

 rows, with a very few tubercles between these ; the size of the tubercles 

 diminishes in the two or three rows nearest the lower margin. The 

 fingers are brown (preserved specimen), short and decidedly deflected, 

 meeting throughout their length, the tips pointed. The lower finger is 

 especially stubby and has several blunt teeth ; the larger, lower finger 



