2 6 CRUSTACEA MALACOSTRACA. III. 



ii. Ianirella laevis n. sp. 



(PL I, figs. 8 a-8 g.) 



Description. The general outline of the body (fig. 8a) with its lateral processes is in the main 

 as in / spongicola and I. Nanseni, but the dorsal surface has no processes or spines, and several other 

 differences are obvious. — The rostrum (fig. 8 b), which is scarcely as long as the sum of the two 

 proximal antennular joints, is somewhat widened towards the middle and here armed at each side 

 with a robust spine; its end is transverse or emarginate, and each angle has a strong spine. Eyes 

 wanting. — First antennular joint (fig. 8 b) about twice as long as broad; the flagellum with 6 joints. 



The lateral processes of the head and of the thoracic segments have the terminal spine much 

 smaller than in I. spongicola, and frequently minute; the processes are on the whole a little or some- 

 what shorter than in the preceding species and without lateral spines; the anterior of the two processes 

 at each side of second to fourth segments is much shorter than the posterior. 



The abdomen (figs. 8 a and 8 g) is distinctly less produced backwards than in /. spongicola, and 

 has its end somewhat narrow and rounded. The four pairs of lateral processes differ extremely in 

 size; third pair are distinctly larger than second, which are much larger than the very small first or 

 fourth pair; each process terminates in an articulated spine. 



Length of the largest specimen, a female without marsupium, 4 mm. 



Remarks. I. glabra Richardson, I. abyssicola Richardson and /. Bonnieri Stephensen have no 

 dorsal processes, but I. la-vis differs from them in the shape of the rostrum, the abdominal processes, 

 etc. — At the antero-lateral margins of first thoracic segment the epimera are visible as a low protub- 

 erance with a spine; at the postero-lateral margins of the three posterior segments the epimera are 

 generally visible from above as very low, but broad and rounded protuberances; in / spongicola such 

 epimera at the same four segments are also visible from above, but scarcely as conspicuous as in I. lavis. 



Occurrence. Taken by the "Ingolf" at two stations. 



Davis Strait: Stat. 24: Lat. 63°o6' N., Long. 56°oo' W., 1199 fath., temp. 2-4°; 7 spec. 

 Stat. 36: Eat. 6i°5o' N., Dong. 56°2i' W., 1435 fath., temp. 1-5°; 4 spec. 



Katianira n. gen. 



Description. Body oblong, rather depressed, in general appearance somewhat similar to 

 lanira (PL II, fig. 1 a). — No eyes. Antennulse with a small number of joints in the flagellum. Antennae 

 shorter than the antennulse (PL II, fig. 1 c); peduncle apparently 5-jointed, as the first joint has nearly 

 or totally vanished, and the three following joints are short; flagellum with few joints. — Mandibles 

 (PL I, figs. 9 a — 9 b) differ from those in lanira especially in having the molar process more slender 

 and, besides, tapering to the rather slender end which is obliquely truncate. Maxillipeds (fig. 9 c) have 

 the second joint broad, its lobe broad though narrower than the joint, with two coupling hooks; 

 third joint narrow; fourth joint formed by the complete fusion of two joints, subtriangular, considerably 

 expanded, and a little narrower than the lobe from second joint; fifth joint -- answering to the sixth 

 in other genera — long, distally produced inwards and forwards in an oblong lobe. Epipod of very 

 moderate size, oblone\ 



