CRUSTACEA MALACOSTRAQA. III. 85 



Remarks. This genus 1 is on the whole allied to Nannonisctts, but differs in the following 

 particulars: the antennulse are normal, not terminating in a vesicle; a pair of epimeral plates are found 

 at first segment, sixth and seventh segments dorsally marked off from one another, and the female 

 operculum is very small. 



Only a single species is known. 



52. Nannoniscella groenlandica n. sp. 

 (PI. VII, figs. 7 a— 7 d; PI. VIII, figs. 1 a— 1 f.) 



Female (with marsupium). Body about two and a half times as long as broad; lateral mar- 

 gins of the major anterior part, viz. head and the four thoracic segments, are, taken as a whole, 

 somewhat convex, while the remaining thoracic segments and the anterior part of the abdomen have 

 the lateral margins nearly parallel, and this posterior section is conspicuously narrower than second 

 or third segment. 



The front area on the head is subtriangular, with the anterior end broadly obtuse and rounded; 

 its lateral margins without keels. The protruding lateral plates reach about to the base of the anten- 

 nal squama (fig. 1 b) and have the end acute. - Antennulse a little shorter than the head; flagellum 

 3-jointed, scarcely as long as the two distal peduncular joints combined. — Antenme with the peduncles 

 almost half as long as the animal; sixth joint considerably longer than the fifth and almost as long 

 as the flagellum, which is 8-jointed, with first joint about as long as the sum of the five following 

 joints; squama nearly as long as third peduncular joint, much longer than broad, acute. 



The four anterior thoracic segments have their autero-lateral angles acute, but scarcely pro- 

 duced and without any terminal spine. The epimeral plates with the end very obliquely cut off, acute. 



Abdomen almost half as broad again as long; the major part of the lateral margins and the 

 terminal margin constitute a semicircular outline. — Operculum (fig. 1 f) very small, longer than broad, 

 increasing in breadth from the base to far beyond the middle, somewhat ovate, but the median half 

 of the posterior margin is a little concave, and the whole posterior margin has a number of long- 

 setae. — Uropods with the peduncle narrow at the base and widening much to the very oblique end; 

 endopod slightly longer than the peduncle, somewhat longer and thicker than the exopod. 



Length of the ovigerous female 2 - 2 mm. 



Remarks. The female is easily distinguished from every other form of northern Asellota by 

 a number of features; unfortunately the male is not known. 



Occurrence. Taken by the "Ingolf at a single place. 



West Greenland: Lat. 64°03' N., mouth of Ameralik Fjord, 5 — 70 fath., shells; 1 spec. 



1 After Pis. VII — VIII had been finished, I discovered that Vauhoffen in 1914 had established the genus Austroniscus, 

 with three antarctic species. It is not improbable that a more thorough examination of various features in his animals may 

 show that one or two — but scarcely the third — of his species are congeneric with my Nannoniscella groenlandica, and if 

 that be the case, the generic name given by me must be cancelled. But at our present state of knowledge I prefer to keep 

 the name Nannoniscella until the male of my new species has been found and some points in the structure of the thoracic 

 segments, etc. of Vanhoffen's animals have been investigated. 



