CUMACEA FROM THE COPENHAGEN MUSEUM. 355 



there seems to have been a median spine or tooth a little in front of the middle of the 

 dorsal surface ; the anterior abdominal somites have strong paired teeth on the dorsal 

 side ; and the exopod of the uropods, with its spine, is not more than one-third of the 

 length of the endopod. The males of the two species are much more alike, but in 

 iV^. suJimii the exopod of the uropods is much shorter than in the species described 

 above, being even shorter, relatively, than in the female (the proportion of one-fourth 

 of the exopod, which I formerly mentioned for the males, is, however, slightly exceeded 

 in some specimens). 



Occurrence. — " Trincomali, Ceylon, surface, 3/1889, K. Fristedt Coll." Copenhagen 

 Museum. Co-types in British Museum. 



Nannastacus gibbosus, sp. n. (Plate XXXIII. iigs. 16-21.) 



Description of adult Female. — Total length 1-8 mm. 



Carapace two-fifths of total length, little broader than deep. The pseudorostrum is 

 very short and truncate and the two parts meet together in the middle line below the 

 respiratory orifice. The antero-lateral margin is deeply concave, the antero -lateral 

 corner produced and triangular, sometimes with one or two teeth at the tip. The eyes 

 are prominent and darkly pigmented. The surface of the carapace is very uneven, but 

 the inequalities are developed in varying degrees in different specimens. The branchial 

 regions are inflated to form rounded bosses, between which the dorsal surface is 

 depressed in the middle line. Posteriorly, the dorsal surface is elevated more or less 

 and there is a small boss on each side just behind the eyes. One or two spinifoi'm 

 teeth are commonly set on the posterior elevation of the dorsal surface and another in 

 the middle a little way behind the eyes, but all of these may be absent. A number of 

 long setae are scattered over the surface of the carapace. 



The first leg-bearing somite is represented only by the pleural plates. The remaining 

 thoracic somites have the pleural plates expanded and rounded. The second and the 

 last somites may have a spiniform tooth in the middle of the dorsal surface, as may 

 also the first abdominal. 



The abdomen is a little shorter than the cephalothoracic region, the fifth somite is 

 about twice as long as deep and rather more than one-third longer than the preceding 

 somite. 



The antennule has the third segment of the peduncle longer than the second and, 

 together with it, longer than the first ; the outer flagellum has a minute terminal 

 segment. 



The third maxillipeds have no exopods ; the basis is about one-third of the total 

 length of the limb. 



The first legs have well-developed exopods ; the basis is about two-sevenths of the 

 total length of the limb. 



The second legs have well-developed exopods ; the basis is inflated and is about 



