Boone, Crustacea, Cruises of "Ara" and "Alva" 221 



The present male measures: carapace, 15 centimeters long; 

 rostral horns included, 14.8 centimeters maximum width; cheli- 

 ped, 33.5 centimeters long. The carapace is broadly pyriform, 

 moderately convex and uneven, slightly longer than wide, the 

 maximum width occurring across the mesobranchial area, with 

 the frontal margin produced into paired, submedian, rostral 

 horns, which are about one-fifth of the total length, and slightly 

 deflected, each horn being a rather broad, triangulate tooth, well 

 separated from its companion. There is a distinct depression on 

 the frontal region, posterior to the rostrum. The superior orbital 

 tooth is strong, roof-like, triangulate; the postorbilal tooth, 

 slightly smaller, is also strong. The inferior preorbital tooth is 

 acuminate, visible dorsally. The dorsad of carapace has the 

 regions strongly delimited, with the areolae sharply defined, the 

 gastric and branchial areas quite tumid ; the dorsal surface is 

 sculptured by a strong, median, longitudinal ridge which bears 

 ten strong, conical, well separated spines or tubercles, these being 

 located, four on the gastric area, one, cardiac, three, intestinal 

 and one, posterior margin. Posterior to the rostrum there is a 

 heart-shape, or oval depression, outlined by about three denticles 

 on either side, the posterior pair of these being the largest. There 

 is also on the gastric region a submedian pair of tubercles, one 

 on either side, in line with the first median gastric tubercle, and 

 also with the hepatic dorsal tubercle. The hepatic lobe is sharply 

 defined, produced marginally into a broad, triangulate, bifid tooth, 

 the anterior lobe of which bears a smaller tooth proximally, on 

 the left side of carapace, this being absent on the right side ; this 

 hepatic lobe protrudes eave-like laterally, above the lateral mar- 

 gin of carapace. On the apex of the dorsad of the hepatic area 

 there are two, spaced, conical tubercles and obliquely in line with 

 these are nine similar spinules or tubercles traversing the outer 

 portion of the branchial region, while on the inner area of the 

 branchial region there are about five to seven, isolated tubercles 

 in approximate oblique series, the most posterior of which is the 

 largest. The outer dorsal marginal portion of the branchial region 

 is tumid and bears, on either side, two pairs of very large, tri- 

 angular spines, one spine of each pair being dorsad to the other, 

 the lower spine of each pair being the larger and protruberant 

 over the rim-like lateral region; there is also a third spine or 

 tubercle on the dorsad of the posterior branchial lateral region. 



