Boone, Crustacea, Cruise of "Alva," 1931 127 



crease in length. Another item of conspicuous difference is to be 

 found in the fingers of the largest cheliped, those of the young 

 specimens being uniformly blunt-tipped, but possessing identical 

 curvature and dentition as the chelipeds do in larger specimens. 

 In a specimen having the propodus of the great chela 5 mm. long, 

 the related carapace is only 2.5 mm. long, so that even in very 

 young adults the great cheliped appears as large or slightly larger 

 than the body. A large male, about 30 mm. body length, has the 

 great cheliped 26 mm. long, 7 mm. high. The chelipeds and body 

 are both greatly compressed laterally. The body is compact, 

 rounded dorsally ; the carapace is short, the length, including the 

 rostrum only about 2 mm. greater than the height of one side 

 of the carapace. The rostrum is an acute narrow triangle with 

 the apex produced as far forward as the first peduncular article 

 of the antennae and separated on each side from the orbital lobes 

 by a deep sulcus, which extends back as far as the base of the 

 orbital lobe. The orbital lobes are moderately large, convex, 

 produced distally into an acuminate short spine, which may vary 

 from rudimentary in young adults to an acute spine, about 1 milli- 

 meter long in the present large adult, in this instance extending 

 beyond the frontal margin. 



The abdominal terga are compact, glabrous, much compressed 

 laterally, and have the epimeral region produced, forming side- 

 walls for a very capacious brood pouch in the females. The telson 

 is one and one-half times as long as the sixth segment, distally 

 rather widely truncate and slightly rounded, setae-fringed; the 

 dorsal telsonic surface is set with three pairs of telsonic spines, 

 subequally spaced in longitudinal series, each line about half-way 

 between the median dorsal line and lateral margin, the third pair 

 of spines being distal. The uropoda are only slightly longer than 

 the telson, with the peduncle produced to a strong triangulate tooth 

 above the base of the outer blade ; the inner blade is smaller, oval, 

 evenly rounded distally; the outer blade has a strong subdistal 

 tooth on the outer lateral margin, the distal margin rounded ; both 

 blades are heavily setose. 



Antennulae with the first peduncular article about 1 milli- 

 meter longer in the dorsal view than the rostrum ; the second joint 

 about one-fifth longer than the first joint; the third joint slightly 

 more than half as long as the second joint, the entire antennular 

 peduncle not as long as the scaphocerite by a distance equal to the 



