Boone, Crustacea, Cruise of "Alva," 1931 107 



the second and third pairs of dorsal telsonic spines; outside of 

 these is another single pair of similarly acute spines, one-half as 

 long as the longest pair and arising from the ventral margin of 

 the outer telsonic angle. There are no telsonic marginal setae pres- 

 ent. The uropoda are slender, the peduncle short, strong, the inner 

 blade quite narrowed, sublanceolate distally, dorsally, with a pair 

 of submedian longitudinal ridges, separated by a deep channel, 

 similar to those of the telson ; the outer blade is differently shaped, 

 wider than the inner blade, but not quite so long as the telson ; 

 the inner lateral margin is convex, tapered distally to an obliquely 

 narrowed, convex, distal margin; the outer lateral margin is 

 straight, armed with thirteen or fourteen articulated spinules be- 

 sides the fixed distal spine ; there is a dorsal longitudinal channel 

 on the outer blade also, but no heavy ridges such as appear on the 

 inner blade. The uropoda are shorter than the telson. 



The eyestalks are short and semiconcealed beneath the cara- 

 pace, lying side by side, only a line of the distal stalk margin ad- 

 jacent to the cornea, showing beyond the carapace. The cornea 

 are large, black, composed of rather large facets ; the cornea is set 

 obliquely terminal upon the stalk, with an excellent dorsofrontal 

 visual range. 



The antennulae have the first peduncular article expanded be- 

 neath the orbit and extending slightly beyond the cornea, distally 

 furnished with short, brush-like setae ; the second article is short, 

 cylindrical ; the third article is similar but one and one-half times 

 as long as the second, the peduncle extending a little over one- 

 half the length of the scaphocerite ; the flagellum is biramous, the 

 inner branch being about as long as the entire carapace, the outer, 

 slenderer branch being about one-third longer than the inner 

 branch. 



The antennae have the basicerite dorsally almost concealed by 

 the appressed carapace but having an acute tooth-like process 

 ventrally, supporting the scaphocerite. The scaphocerite is four- 

 fifths as long as the carapace, with the outer lateral margin thick- 

 ened and not entirely straight, the inner lateral margin oblique, 

 tapering distally toward the outer lateral margin and forming an 

 acuminate stylet ; there is no inner convex distal portion of the 

 scaphocerite whatever, this oblique inner lateral margin being 

 fringed with long web-like setae. The carpocerite is cylindrical 

 and extends half the length of the scaphocerite or to about midway 



