NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



63 



in the mid-ventral line posterior of the nerve ring and a little anterior 

 of the level of the cervical papillae (fig. 74). The mouth (fig. 75) 

 is elongated dorso-ventrall}^ and bounded by two lateral lips with a 

 thick internal border ; each lip bears two large papillae. The mouth 

 opens into a very short buccal cavity with 

 a thick lining. The esophagus is notably 

 short; it is one-twentieth of the total length 

 of the body of the female and one-twenty- 

 second of that of the male. The nerve ring is 

 situated one-fifth of 

 the length of the 

 esophagus from the 

 a n te r i o r extremity. 

 There is no division 

 into muscular and 

 glandular portions. 

 The posterior extrem- 

 ity at the union with 

 the intestine has a j 

 valvular structure. 



Male 18.5 to 22.5 

 mm. long and with a 

 maximum thickness 

 of 480 \i. The short, 

 conical tail termi- 

 nates in a small 

 mucronation. The 



200 jji. 



73. 



75. 



Figs. 73-75.— Seuratum tacapense. 73, A fkagment of cuticle. Magnified. After Seueat, 1915. 

 74, Anterior extremity of body. After Seurat, 1915. 75, a, Head viewed from the front; 6, 



POSTERIOR extremity OF MALE, VENTRAL VIEW. AFTER SEURAT, 1915. 



distance from the cloacal aperture to the posterior extremity 

 of the tail is 250 ]x. There are two straight symmetrical bursal 

 alae (fig. 75). From a distance anterior of the cloacal aperture the 

 ventral region of the body is covered with about 20 longitudinal 

 rows of cuticular shields which become confluent a short distance 

 anterior of the cloacal aperture; the circumcloacal region and the 

 bursal alae are entirely covered with these shields, with a resultant 

 verrucous appearance; only the inferior lip of the cloacal aperture 



