14 



THE ROUNDWORMS OF DOMESTIC SWINE. 



two-thirds of a complete circle. The thickened cuticle seems to 



project downward into the body (fig. 2). 



Ciurea (1911) depicts 10 tactile papillae located on the ventral 



surface of the body of the male, close to the tip of the tail. These 



could not be seen in the specimens studied 

 by the writer. The rectum (fig. 4) of the 

 female is about 80 /z in maximum width and 

 nearly as long as the distance from the anus 

 to the tip of the tail. In the region immedi- 

 ately posterior of the anus several fine lines 



FIG. 7. Ar due nna strongylina. 

 Short spicule with retractor 

 muscles viewed from right side. 

 ret. m., retractor muscles; *. sp., 

 short spicule. X 80. (Original.) 



can be seen beneath the 

 cuticle, converging toward 

 the base of the anus. These 

 are probably muscle fibers 

 controlling the rectum, and 

 are seen in the females of 

 many nematodes. A pair 

 of papillae close to the tip 

 of the tail extend laterally 

 to the edges of the caudal 

 cuticle on the ventral 

 side. 



In a cross section of Ar- 

 duenna strongylina (fig. 9 of 

 the present article) , Ciurea 

 (1911) shows that the in- 

 terior of the lateral wing 

 is filled with a substance 

 shaped like the letter V 

 when viewed in this posi- 

 tion. In its reaction to 

 hematoxylin it resembles the thickened wall of the pharynx. 



The same drawing (fig. 9) also shows that the vagina first passes 

 between the cuticle and muscular wall as it crosses the body to ex- 

 tend along the right side. In several of the specimens examined by 

 him, Ciurea (1911) noticed a drop of hardened cement at the opening 



Ho mm. 



FIG. 8. Arduenna stroru/yUna. Posterior end of body of 

 male, viewed from left side, cl., cloaca; int., intestine; 

 I. b. w., left bursal wing; po. p., postanal papillae; pr. p., 

 preanal papillae; pr. r. , perianal ring; sh. I. sp. , sheath of long 

 spicule; sh. s. sp., sheath of short spicule; . sp., short spi- 

 cule; v. def., vas deferens; v. r. c., ventral ridge of the cuticle, 

 X 58. (Original.) 



