173 



and about twice as long as the basal part ; penultimate pair with the outer ramus 

 somewhat shorter than the inner, and armed, near the tip, with a very long 

 and slender spine. Telson oblong oval, about twice as long as it is broad, with 

 4 pairs of dorsal denticles, and a single pair of apical spinules, tip blunt t-d. 

 Body whitish, pellucid, mottled on the sides with pinkish and yellowish specks. 

 Length of adult female 14 mm, of male somewhat less. 



Remarks. In its general appearance, this species bears some re- 

 semblance to the above-described A. assimiliy, though being, perhaps, a little 

 more slender in form. On closer examination, it is however easily distinguished 

 by the rather different structure of the last pair of pereiopoda, as also by 

 the form of the last pair of epimeral plates of metasome, finally, by the very 

 slight dorsal carina of the 1st segment of urosome. 



Occurrence. The species occurs along the whole coast of Norway, 

 from the Christianiafjord to Vadso, in moderate depths, but seems to be most 

 abundant in the arctic region. 



Distribution. Arctic Ocean: Greenland, Labrador, east coast of 

 North America, Iceland, Spitsbergen, the Kara Sea; British Isles, Kattegat, 

 Bolmslan. 



7. Ampelisca spinipes, Boeck. 



(PL 60, fig. 2). 

 Ampelisca spinipes, Boeck, Crust, ainphip. hor. & arctica, p. 143. 



Cephalon about the length of the 3 anterior segments of mesosome 

 combined, slightly tapering anteriorly, tip nearly transversely truncated, with 

 the lower corner somewhat less projecting than the upper. First pair of coxal 

 plates obliquely expanded distally, and rather broad in their outer part; 4th 

 pair nearly as broad as they are deep, inferior edge somewhat oblique, and 

 about the length of the hind margin. Metasome slightly carinated dorsally; 

 last pair of epimeral plates not produced at the lateral corners, and nearly 

 right-angled. First segment of urosome deeply impressed at the base dorsally. 

 especially in the male, and exhibiting, behind the depression, a rather high 

 and conspicuous, rounded carina. Corneal lenses small, but distinct, the lower 

 pair somewhat remote from the inferior corner of the front, underlying pig- 

 ment somewhat irregular in form, reddish, partly coated with chalky white. 

 Superior antennae in female much larger than in any of the preceding specif-, 

 and nearly half as long as the body, 1st joint of the peduncle rather strong, 

 2nd, as usual, much more slender and elongated, tiagellum about 3 times lon- 

 ger than the peduncle, and composed of about 32 articulations provided 

 posteriorly with fascicles of slender setae; those in male still more elongated, 



