Nematode from the Norwegian Beaver, 



283 



CEsopliagns. — The ce.sopliaf!;us is straight, slender, and 

 tapering gradually towards its cephalic end. It is 0'G(j mm. 

 in length in the male and 0"G8 mm. in the female. The 

 maximum diameter of the a3Sophagus is at its caudal end. 

 It is 0*08 mm. in diameter in both sexes. 



Chyle Intestine. — The chyle intestine in both sexes ))ursues 

 a straight course along the axis of tiie body. The intestinal 

 celU are not pigmented. The rectum in the temale is a 



Fig. 2. 



200 fx 



Female tail. 



short narrow canal 0*08 mm. in length. The anal opening 

 is not raised above the surface, and lies in the mid-ventral 

 line 0"37 mm. from the tail-end (fig. 2). 



Nervous System. — The nerve-ring surrounds the oesophagus 

 0'32 mm. from the cephalic end in both sexes. 



Excretory System. — The excretory pore passes through the 

 cuticle in an oblique direction, running caudad from the 



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