BY H. A. BAYLIS. 



305 



which measures 0.22-0.25 mm. in length and 0.23-0.24 mm. 

 in width. There are broad lateral cervical alae, beginning 

 immediately behind the mouth and extending to a point a 

 little behind the oesophageal bulb. The diameter of the head 

 is about 0.07 mm. The nerve-ring is situated at 0.3—0.35 

 mm., and the excretory pore at 0.5—0.55 mm. from the anterior 

 end in both sexes. The cuticular striations are very fine and 

 faint, but more conspicuous on the cervical alae. 



The structure of the buccal cavity, whicli is barely indicated 

 in Eatzel's figures, is very curious. The cavity is about 0.08 

 mm. in length, and is divided into an anterior portion of 

 0.02 mm., with 

 fairly thick cuti- 

 cular walls, and a 

 much longer pos- 

 terior portion, the 

 walls of which are 

 much thicker and 

 darker in colour, 

 and end in front 

 in a serrated 

 edge. This por- 

 tion of the cavity 

 increases slightly 

 i n width from 

 before back- 

 wards. At its 

 base, springing 

 from the cuticular 

 lining of the an- 



Fit 



Head of male; 



1. Suhulura perarmata. 

 dorsal view. 

 terior portion of 



the oesophagus, are the three large and three small tooth-like 

 structures described by Eatzel. The larger teeth are apparent- 

 ly flattened and blade-like, and the smaller teeth alternate with 

 them. 



The tail is tapering and drawn out to a fine point in both 

 sexes. In the male it measures about 0.25 mm. in length. 



There are no caudal alae. The preanal sucker is situated 

 at about 0.5 mm. from the cloacal aperture, not from the tip 

 of the tail, as stated by Katzel. The spicules measure about 

 2.75 mm. in length, and invariably show the remarkable 



