B57 



changed in accordance therewith. It is easily distinguishable from any of 

 the other forms belonging to this family, by the peculiar nodiform projections 

 of the 2 anterior segments of metasome. 



Occurrence. I have met with this form not rarely in several places, 

 both off the south and west coasts of Norway, as also in the Trondhj ems- 

 fjord, in depths varying from 30 to 100 fathoms. Off the Finmark coast, on 

 the other hand, it seems to be wholly absent. 



Distribution. British Isles (Robertson). 



Gen. 4. Parapleustes, Buchholz, 1874. 



Syn.- Paramphithoe, Boeck (part). 

 Pleustes, Boeck (part). 

 Amphithopsis, Boeck (part). 



Body, as a rule, less slender than in the preceding genus, sometimes 

 even very robust of form. Cephalon slightly produced in front, and having 

 the postantennal corners more or less projecting. Coxal plates of middle 

 size, and successively increasing to the 4th pair. Superior antennae less elon- 

 gated than in Stenopleustes, though considerably longer than the inferior ones. 

 Anterior and posterior lips as in the preceding genera. Mandibles with the 

 molar expansion well developed and of cylindrical form, exhibiting the usual 

 fluted triturating surface, palp rather large, with the last joint a falciform 

 curve. First pair of maxillse well developed, palp slightly dilated distally, 

 basal lobe provided with 2 plumose setse. Second pair of maxillse and max- 

 illipeds about as in the preceding genus. Griiathopoda somewhat unequal, 

 the posterior ones being, as a rule, much stronger than the anterior and more 

 pronouncedly siibcheliform. Pereiopoda less elongated than in the genus 

 Stenopleustes, and sometimes of very robust structure. Uropoda and telson 

 about as in the preceding genera. 



Remarks. The present genus, established by Buchholz, is chiefly 

 distinguished from the other genera belonging to this family, by the structure 

 of the mandibles, the molar expansion of which exhibits the cylindrical form 

 usually met with in the typical Amphipoda, Moreover the gnathopoda are 

 more or less unequal, the posterior ones being sometimes very strongly 

 built. Besides the 3 Norwegian species described in the sequel, the Ampni- 

 lltopsis Olriki of Hansen would seem to belong to this genus. 



4 '< Crustacea. 



