OF THE COMMON NEMATODE OF THE DOGFISH. 



451 



The body is slightly attenuated towards the anterior end, and 

 the head (text- fig, 1) is chai-acterized by the presence of a 

 peculiar cuticular collar. ]t was probably the presence of this 

 collar which suQ-o-ested to Van Beneden his afeneric name 



Head of Frnleptus scillicola. 

 Letteeing oe Figuees. 



Coronilla. There are two rounded, protruding, lateral lips, each 

 of which bears a single conical tooth. Linstow (9) mentions in 

 addition " interiorly a small pointed cone," but I have failed to 

 find any evidence of this either in whole mounts or sections. 

 The excretory pore is exceedingly small, and is situated in the 



