614 



PROCEEDINGS OF THE NATIONAL MtJSEUM. 



VOL. 41. 



BATHYCUMA (?) LONGICAUDATA, new species. 



Immature female. — Total length, 18.5 mm. 



Carapace a little more than one-fourth of total length, its height a 

 little greater than its transverse width and about three-fifths of its 

 length ; its dorsal edge arched and keeled, at least in its anterior half, 

 where it bears a double series of fine serrations, for the most part 



Fig. 10. — Bathtcuma (?) longicaudata, immature female, from the side. 



alternating. The pseudorostrum is short, pointed, and slightly 

 upturned. There is a well-marked, angular, antennal notch defined 

 below by a bluntly pointed antennal tooth, the lower margin of which 

 is obscurely serrated. There is no distinct eye, and the ocular lobe 

 is reduced to a narrow process carrying the serrated dorsal crest for 



a little way between the plates 

 of the pseudorostrum. The free 

 thoracic somites diminish rapidly 

 in height; the dorsal surface in 

 the third and fourth is raised in a 

 transverse ridge. The abdomen 

 exceeds, by more than one-fourth, 

 the length of the cephalothoracic 

 region, and is very slender, the 

 vertical height of the anterior 

 somites being little more than a 

 tliird of that of the carapace. All 

 the somites except the last have 

 a pair of dorsal and a pair of 

 dorso-lateral ridges, while a pair 

 of less sharphf marked ventro- 

 lateral ridges on the anterior 

 somites become more pronounced 

 and lateral in position on the last two somites. The last somite 

 is produced, as a prominent rounded lobe, between the bases of the 

 uropods. 



The second and third segments of the antennule are subequal and 

 much more slender than the first. The tliird maxillipeds have the 



U 12 



Figs. 11-12.— Bathycuma (?) longicaudata, imma- 

 ture FEMALE. 11, Third maxilliped; 12, first 

 leg. 



I 



