66 BRITISH COPEPODA. 



foot has only two joints. The terminal spines of the 

 swimming feet are sword-shaped, rather slender, and 

 finely serrated (fig. 7). The first segment of the female 

 abdomen bears three plumose spines, one of which is 

 stronger than the other two, and the second segment 

 is produced laterally into a papilla for the attachment 

 of spermatophores. Caudal segments short, about as 

 long as the last abdominal segment, setose on the 

 internal margins and bearing five strongly plumose 

 and rather rigid apical setse which are considerably 

 shorter than the abdomen. Length i^-th of an inch 

 (1*6 mm.). Colour brown. 



Except in littoral situations this species seems to be 

 at least as common in the British seas as the following 

 (0. hamatus). It is taken frequently in the North Sea 

 and in the Atlantic by the towing net; indeed few 

 gatherings thus made, if at all good ones, are entirely 

 without it. I have memoranda of its occurrence off 

 the West Coasts of Scotland and Ireland, the East of 

 England and Scotland, amongst the Channel Islands, 

 between Cornwall and Cape Clear, &c. It occurs, 

 too, amongst dredged material so frequently that it 

 can scarcely in all cases have been captured by the 

 dredge on its way up to the surface. 



