Boone, Criistaeea, Cruise of "Alva," 1931 79 



above the lateral process, this upper conical process having the 

 apex directed outward laterally. 



The second pleopoda of the male have the inner branch special- 

 ized, consisting of a small blade similar to, but smaller than, the 

 inner blade of the third pleopoda, and arising at the inner side of 

 this is a third organ, consisting of a slender, twisted, stem-like 

 base, supporting a bulbous, subspherical distal portion which has 

 on its ventral surface a convoluted groove. 



Between the bases of the fifth pair of legs the male has a me- 

 dian sulcus, on either side of which there is a subtriangulate, 

 plate-like border. Anterior to this sulcus there is a transverse 

 hard bowed or curved ridge which has also a narrowed sulcus 

 anterior to it. 



The female thelycum consists of a transverse calcareous bar, 

 thickened medially, and with the posterior margin convex ; on the 

 anterior side this bar gives rise to a median, rounded tubercle 

 and a pair of curved, somewhat auricular bars, which have the 

 free ends rounded, the ventral surface flat or slightly excavate 

 distally. On the inner side, near the distal end of each of the auri- 

 cular bars, there is a rounded convex tubercle. Very young fe- 

 males, three inches or less in length, lack this and have the auricular 

 bar subacute distally. These bars are contiguous with the laminate, 

 lozenge-like plates that arise, one each, from the inner ventral 

 border of the basal joint of the fourth pair of legs. Each of these 

 plates has the anterior margin slightly rounded. The general 

 contour outlined by these bars between the fifth and fourth pairs 

 of legs is that of a horse-shoe, with the free ends directed forward. 

 Beneath these plates of the fourth pair of legs is seen a triangu- 

 late arrangement of the ventral plates, with the apex of median 

 plate directed posteriorly. The first pair of pleopoda of the female 

 are uniramous. 



Pattern : The pilosity of the carapace forms a very definite 

 marbled pattern as follows: an elongate patch on either side of 

 the rostral carina, this patch branching anteriorly, the outer 

 branch occupying the median area of the space above the orbital 

 ridge and in turn uniting with an interrupted branch that extends 

 in broken series to the hepatic sulcus. A third branch runs out 

 from the main subdorsal patch and extends along the lower bor- 

 der of the cervical ridge. There is also a second or posterior sub- 

 dorsal patch consisting of two oval lobes, from the outer of which 



