Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 183 



back, its outer lateral margin slightly convex, the sixth segment is 9.5 

 mm. long, with the lateral margin straight, a small spine at the lower 

 posterior distal angle; a triangular process on each side on the base 

 of the telson, the median posterior margin straight. The telson is 9.5 

 mm. long, or about 3 mm. shorter than the uropoda, with the upper 

 surface convex, the distal margins rounded and ciliated. 



The peduncle of the uropoda is produced into a small, triangular 

 process above the base of the inner blade and a much larger, tri- 

 angulate process above the outer blade; the blades are subequal in 

 length, the inner one regularly oval and slightly the narrower, with 

 a median longitudinal ridge and with the margins ciliated. The outer 

 blade is the wider, with a light median keel and also with a heavier 

 keel running obliquely to the subdistal spine of the outer lateral mar- 

 gin ; the distal margin is convex, ciliated. 



On the ventral surface there is a very acute, conical, forward- 

 directed spine in the median line at the apex of the sternal plastron. 

 In the median line of each the first, second, third, fourth and fifth 

 segments there is a short, downward-directed spine placed between the 

 pleopoda, and at the median posterior margin of the sixth segment 

 there is a sharp, conical spine directed straight back. 



The eye is short, close-set, projecting only slightly beyond the ros- 

 trum ; the stalk has a small, tongue-like projection, tipped with a low 

 tubercle on the cornea; the cornea is terminal, spherical, made up of 

 very fine hexagonal facets. 



The inner antennae have the peduncular article short, shallowly 

 excavate beneath the ej^e ; with a large, lobate process on the outer 

 side, protecting the eye; the second and third articles short, com- 

 pressed dorsoventrally, the flagellum with the outer whip the thicker, 

 composed of 38 rings and fringed on the lower margin with long, 

 plumose setae ; the inner flagellum consists of a basal article two-thirds 

 as long as the outer whip and 25 short articles and is also very setose 

 on both margins. 



The antennae have a short, basal article, with a rounded triangle 

 showing on the upper surface and a small spine at the outer distal 

 angle which is shorter than the pterygostomian spine ; the scaphocerite 

 is large with the outer margin thickened and terminating distally in 

 an acute triangulate spine which extends beyond the inner convex 

 lobe of the scaphocerite. There is also a median longitudinal rib in 

 the scaphocerite. The second article is short, the third long, slender, 

 cylindrical ; the flagellum is very slender, multiarticulate, 65 mm. long. 



