28 G. 0. Sårs. 



The form of the body (see tigs. 1 and 2), as compared 

 with that in the preceding species, appears somewhat shorter 

 and thicker, and the proportions of the several sections is 

 rather different. The head in the female (fig. 1) is of a 

 similar shape to that in Streptocephalus gracilis. In the 

 male (fig. 2) it is comparatively larger, and its frontal part 

 exhibits, in a dorsal view of the animal (fig. 3), an almost 

 pentagonal form, projecting somewhat between the bases of 

 the antennæ, without, however, forming any true frontal 

 lobe. The cervical segment is well defined, and in the 

 female is almost as long as the fore-part of the head. Its 

 lateral expansions, containing the shell-gland, are very con- 

 spicuous. 



The trunk has the normal number of segments, but 

 appears somewhat depressed, its width considerably exceed- 

 ing its height (comp. figs. 2 and 3). 



The genital region in the female (fig. 1) is very large, 

 about equalling in length half the trunk, and it has its 2 

 segments only defined dorsally. Ventrally this region is 

 continued in the very capacious marsupium, which is not, 

 as in Streptocephalus, prolonged behind to a freely projecting 

 pouch. In the male (figs. 2 and 3) this region is consider- 

 ably smaller, though more than twice as long as the suc- 

 ceeding caudal segment. 



The tail is comparatively much shorter than in the 

 preceding species, and does not nearly attain the length of 

 the trunk. It tapers slightly distally, and has the segments 

 very sharply marked off from each other, and considerably 

 broader than they are long. The last segment, as usual, is 

 the shortest, somewhat flattened, and, especially in the male, 

 expanded distally (see fig. 3). 



