96 BRITISH FEESHWATICR EHIZOPODA. 



Under the name of N. collaris, Leidy included 

 several forms now recognized as distinct, but, so far as 

 can be gathered from his description and figures, that 

 here described must be regarded as typical of the 

 species. It differs from N. tincta (Leidy), and N. 

 fiahellulum Leidy (its nearest allies) in having a 

 test which is not suddenly contracted to form a short 

 cylindrical neck ; it is wider at the mouth than 

 either of these ; and almost invariably the sides, if 

 not dilated, cease to converge just above the basal 

 angles. The species is one of the commonest in 

 sphagnous swamps. Being more elongated in pro- 

 portion to its breadth than either N. tincta or N. 

 Hahellulum, and having its sides straight or only 

 slightly convex, N. collaris may without difficulty be 



Fig. 85. — JVebete eoKaris in conjugation. Dunham, Cheshire, x 250. 



differentiated from the species here named. One not 

 familiar with the nice distinctions between varioiis 

 allied forms would be more apt to confuse it with the 

 more elongated N. tuhulosa Penard, or N. amrricnna 

 Taranek. These however, as will be seen by a 

 reference to the descriptions, have characters which 

 sufficiently distinguish them. 



Nebela collaris is the only rhizopod whose empty 

 test we have seen taken possession of by a higher 

 organism. Repeated instances occurred in one of 

 Mr. Hopkinson's gatherings from Capel Curig [Moel 

 Siabod] in the summer of 1908, of a species of roti- 

 fer* using it as a dwelling-place — whether adventi- 

 tiously or by design was not apparent. The animals 

 (usually only one in a test) were very active, protruding 



* [Apparently a Callidina.] 



