NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



15 



one-seventh of total body length. Tail (fig. 85) terminates in a 

 dorsal point 200 (i long. There are two narrow bursal alae. There 

 are three pairs of caudal papillae, one pair preanal and two postanal; 

 the second pair of postanal papillae is pedunculated and sustains the 

 bursal alae. The caudal glands appar- 

 ently open between the two pairs of post- 

 anal papillae. The spicule is 300 \k long 

 and is slightly enlarged at its free extrem- 

 ity. The gubernaculum is 70 \k long. 



Female attains a maximum length of 

 about 12.7 mm. and a thickness of about 

 COO [x. Tail long and narrow, one-fourth 

 as long as the body (fig. 8C). Esopha- 

 gus one-sixth to one-twelfth of body 

 length. Ovaries 5 mm. long, slightly 

 looped, blackish from reserve granules. 

 Vagina is everted to the exterior to a dis- 

 tance of 125 \i or more (fig. 87). In 

 larvae in the fourth stage, 2.7 mm. long, 

 and in some small and immature females, 

 7.2 to 9 mm. long, the vulva, which is 

 about one-third of the length of the worm 

 from the anterior extremit}^, presents a 

 prominent anterior lip and opens into a 

 vagina lined with a thick cuticle; at the 



other end of the 



vagina is the 



ovijector. No 



spermatozoa are 



found in the 



receptaculum 



s e m i n i s. I m - 



mediately after 



the fourth molt, 



and long before 



sexual maturity 



is attained, the 



a 



Fig. 84.— OxYUEis hilgerti. 

 Anterior extremity, lat- 

 eral VIEW, c, Cephalic 

 GLAND. After Seurat, 1915. 



[It is not clear from Seurat 's fig- 

 vires whether this scale belongs 

 with this figure or not.] 



female, then 



Fig. 85.— OxYtJRis hilgerti. Pos- 

 terior extremity of male, ven- 

 tral view. After Seitrat, 1915. 



usually about the 



same size as the 



male, 3 to 5 mm. 



long, is fertilized. Immediately after, the eversion of the vagina 

 occurs, thereby automatically preventing further attempts at fer- 

 tilization. Young females when fertilized show little development 



