Boone, Crustacea, Cruise of "Alva," 1931 25 



mens, the median distal margin is coarsely crenulate and more eon- 

 vex than in the older specimens. The peduncle of the uropoda is 

 thickened, with a distinct short, curved sulcus on the posterior half 

 of the portion basal to the exopodite; a distinct wide longitudinal 

 sulcus sets apart the portion basal to the endopodite. On the dorsal 

 surface, there is a short, sharp spine, at the outer posterior angle 

 above the base of the exopodite. On the inferior margin of the pedun- 

 cle, there is a striking, bifurcate process, arising from the distal mar- 

 gin and consisting of two well separated spines, both of which are 

 curved outwardly and backward, the anterior spine being the shorter, 

 about one and one-third to one and one-half times the length of the 

 peduncle, very tapered and acuminate, composed of three longitudinal 

 carinae alternating with three grooves. The second, or posterior spine 

 is about twice as long as the first, its apex, being almost on a line 

 with the posterior margin of the telson. The proximal article of the 

 endopodite bears a fixed short spine at the apex of its inferior margin ; 

 along its outer lateral margin there are eight to ten articulated spines, 

 successively increasing in length a little from proximal to distal, the 

 distal one extending above the base of the second article. This second 

 article is ovate, about twice as wide as long, with finely crenulate 

 margin and a fringe of web-like setae. The endopodite is unequally 

 subovate, being longer and wider, with the outer lateral margin 

 slopingly rounded and confluent with the inner lateral margin which 

 is nearly straight ; the entire margin is finely crenulate and setose. 



The ophthalmic segment has its anterior margin acutely pointed, 

 the dorsal processes consist of a pair of conspicuous wide lobes, each 

 of which terminates in a small tooth or spine at the outer lateral 

 angle, on either side of the rostrum. The eyes are very large, reni- 

 form, the stalk short and thick, compressed, its axis oblique; the 

 cornea are very large, dorso-terminal, the long axis very oblique, 

 slightly longer than the median length of the rostrum and two and 

 one-third times the diameter of the cornea, cylindrical, with a median 

 transverse constriction and both distal ends convex. 



The inner antennae have the three peduncular articles subequal, 

 elongate, compressed, cylindrical, each slightly enlarged distally, the 

 inner whip of the flagella is about twice the length of the peduncle; 

 the outer whip has its longer branch subequal to the inner branch, 

 and its shorter branch three-fourths as long as the other branch. All 

 three whips are very finely articulated. 



