174 BEITISH COPEPODA. 



at any rate in the littoral and laminarian zones, 

 occurring usually in considerable numbers, though 

 never in the countless swarms of some of the larger 

 oceanic species. It is occasionally found amongst 

 dredged material, but possibly this may, in some cases 

 at least, arise from its being entangled during the 

 upward passage of the dredge through the water ; in 

 the open sea it is often taken by the tow-net. Dr. 

 Glaus has taken it both in the North Sea and in the 

 Mediterranean, M. Boeck on the coast of Norway, and 

 Fischer in Madeira (?). With so wide a range of 

 distribution we need not wonder that its range of 

 variation is likewise great, and Dr. Glaus has pointed 

 out (loc. cit.) some of the characters, especially the 

 lengths of the antennal joints, which are thus liable 

 to vary ; I have no doubt that a minute examination 

 would show great diversity of structure perhaps even 

 some well-marked races or varieties in the species as 

 it exists on our own shores. At one time, indeed, I 

 was disposed to think that two or more species had 

 been grouped under one name, but further examina- 

 tion showed this idea to be untenable, and without 

 more time than I had at my disposal it would have 

 been impossible to attempt satisfactorily any un- 

 ravelling of the complicated problems connected with 

 race variation. 



