340 



densely edged with slender spines; last pair scarcely reaching beyond them, 

 rami about the length of the basal part, and only edged with very small 

 denticles. Telson regularly quadrangular in form, about as long as it is 

 broad, terminal edge straiglit. Body pellucid, whitish, with a faint tinge 

 of flesh-colour. Length of adult female 15 mm. 



llemarls. — As above mentioned, this form was first described by ray 

 late father, Prof. M. Sars, as Leucothoe phyllonyx. Subsequently tlie same 

 form was foiind by Bruzelius, and described by him under another name, viz., 

 CEdiceros obhistis, which latter denomination was also adopted by Goes, and 

 likewise, at first, by Boeck. Subsequently, however, the last-named author 

 justly restored the much older specific name proposed for this form by my 

 late father, and made it the type of a new genus. From the other CEdiceridae 

 this form is at once distinguished, among other characteristics, by the 

 absolute want of any frontal projection. 



Occurrence. — The present form is fo\;nd along the whole coast of 

 Norway, from the Christianiafjord to Vadso, in greater depths, ranging from 

 50 to 400 fathoms, occurring in some places even in great abundance. But 

 more generally only young specimens are met with during the summer months. 

 Mr. Schneider, who has recently published a most interesting paper on the 

 biological relations of the Amphipoda, therefore opines, that this form has 

 only an annual existence, and that its breeding is restricted to the early 

 spring, an opinion that is quite confirmed by my own observations. 



Distribution. — Arctic Ocean widely distributed: Greenland (Hansen), 

 Iceland (Norw. North Atl. Exped.), Spitsbergen (Goes), Franz Josephs Land 

 (Heller), the Barents Sea (Hoek), the Murraan coast (Jarzynsky), the Kara 

 Sea (Hansen), the Siberian Polar Sea (Stuxberg); Bohuslan (Bruzelius); 

 North Sea 60 M. north of Peterhead (Metzger). 



Gen. 13. Aceroides', a. O. Sars, n. 



Form of body somewhat less elongated than in the preceding genus. 

 Cephalon with a small but distinct rostral projection in front. Coxal plates 

 very small, the 1st pair scarcely expanded distally. Eyes inconspicuous. 

 Superior antennae in female longer than the inferior ones, with comparatively 

 short peduncle, and very fully -developed flagellum. Anterior lip rather broad, 

 and nearly transversely truncated at the tip. Mandibles less strong than in 



') As a genus Aceropsis has beeu uamed, without however any diagnosis, by Dr. Stuxberg, 

 I have thought it right to change the generic name inserted in the plate. 



