CANTHOCAMPTUS. 51 



inner branch (fig. 14) are reduced in size, and the 

 small outer apical seta (a) is thickened and spine-like. 

 The basal joint of the fifth foot (fig. 16) has only two 

 principal spines on its inner segment. Abdomen 

 composed of five segments. 



This pretty and graceful species occurs commonly 

 in small freshwater pools and ponds throughout the 

 country. I have no record of its occurrence at any 

 great elevation, nor have I ever found it in lakes or 

 very large sheets of water. The reason of this I take 

 to be that it prefers shallow water where the vegeta- 

 tion is abundant ; its colour seems to vary with the 

 character of the plants and Infusoria upon which it 

 probably feeds. The only considerable pieces of water 

 in which I have found it are the lake in Axwell Park 

 near Gateshead, and Holy Island Lough (Northum- 

 berland), but both these are really, as to size and 

 character of vegetation, big ponds rather than lakes. 



Miiller's figures of Cyclops minutus, though in some 

 respects inaccurate, as was unavoidable in the absence 

 of the modern microscope, doubtless refer to the 

 species under consideration. Jurine, however, dis- 

 carded the name minutus, under the idea that still 

 smaller species of the genus might subsequently be 

 found, a reason which might have had some weight 

 had Muller called his animal minutissimus, but to which 

 we can scarcely allow any, as matters stand. It seems 

 to me due to the older author to retain his specific 

 name which has the claim of undoubted priority. 



The females are very commonly found with a long, 

 narrow, and curved spermatic tube attached to the 



