Nematode from the Norwegian Beaver. 



287 



Genital Cone. — The genital cone is a massive structure 

 protrudincr from the floor of the bursa, and having a rounded 

 apex pierced by the cloacal canah There is a large papilla 

 on either side of the cloaca! opening. 



Spicules. — Tlie two spicules are equal and similar. Each 

 is 0*185 mm. in length. The cephalic extremity is cup- 

 shaped, hollow, and has a thickened rim (fig. 6). Tlie spicule 

 has a groove along its ventral aspect. The caudal end is 

 rounded, carrying a knob-like end. There is no accessory- 

 Fig. 6. 



y^4 



^J 



*C' 



Fig. 7. 



50 /i 



SO fi 



Fig. 6. — Ventral aspect of one spicule. 

 Fig. 7. — Ovum. 



piece. At the bases of the spicules there are two empty sacs, 

 from which the spicules have been apparently protruded. 



Termination of the Female. — The female tail is 0*37 mm. 

 It ends bluntly and is not provided with papillae. 



Ova. — The ova, which are laid in the morula stage, are 

 oval, thin-shelled, and measure 85 jm in length and 55 /a in 

 breadth (fig. 7). 



Habitat. — The stomach of the European beaver, " Castor 

 Jiber/^ Norway. 



