ART. 13 TEEMATODE PAIJASITES OF MARINE MAMMALS PRICE 37 



ternating tranverse rows. Oral sucker slightly subterminal in posi- 

 tion, 60/x to 75/x, in diameter. Prepharynx SOjw, to 33/x long ; pharynx 

 ovoid to spherical in shape, 29/x, to 33/* wide; esophagus 18/a long; 

 intestinal eeca relatively wide and extending to near the posterior 

 end of the body, their blind ends being hidden by the testes. The 

 acetabulum is circular, 52/a to 60/1 in diameter, situated from 235/* to 

 259/A from the anterior end of the body and inclosed in the shallow 

 genital sinus. The genital ducts open into the anterior part of the 

 sinus and two elliptical gonotyls are present, one on each side of the 

 genital aperture. The seminal vesicle is voluminous, more or less C 

 shaped, and lying to the right of the acetabulum; there is a sharp 

 constriction of the vesicle near the level of the posterior margin of 

 the acetabulum which divides it into an anterior piriform part and 

 a posterior globular part. The testes are somewhat triangular in 

 outline, 81/i to 96/t by Sl/i to llO/i, and are situated side by side in the 

 posterior fourth of the body. The ovary is more or less triangular 

 in outline, 55/i to To/i by 67/a to 92/x,, situated a short distance cephalad 

 of the right testis. The seminal receptacle is spherical, 44ju, in di- 

 ameter, and situated dorsal to the ovary and right testis. The vitel- 

 laria consist of large, closely packed follicles, which extend from the 

 level of the acetabulum to the level of the anterior margin of the 

 testes ; the follicles are distributed over the entire dorsal surface but 

 ventrally they are chiefly lateral except near the intestinal bifurca- 

 tion where they form a distinct band across the body. The uterus 

 consists of a few loops confined to the intercecal field between the 

 anterior margin of the testes and the genital aperture. The eggs are 

 33/i long by 18/* wide, golden yellow, and slightly piriform in shape. 



Host. — Zalophus calif omianus. 



Location. — Small intestine. 



Distribution. — North America (United States — National Zoo- 

 logical Park, Washington, D. C). 



Type specimens. — U.S.N.M. Helm. Coll. No. 30808; paratypes, 

 No. 26652. 



Remarks. — Apophallus zalophi is easily distinguished from A. 

 donious, the only species of the genus with which it might possibly 

 be confused, by its size, relative length of the prepharynx and 

 esophagus, and by the distribution of the vitellaria. A. zalophi is 

 on the whole a much smaller species than A. donicus and the body is 

 somewhat thicker. The prepharynx is longer than the esophagus in 

 A. zalophi, while in A. donicus the reverse is true. The vitelline fol- 

 licles are relatively larger in A. zalophi and extend from the level 

 of the pharynx to the anterior margin of the testes, while in A. 

 donicus the follicles extend from about midway between the 

 pharynx and intestinal bifurcation to the posterior end of the body. 

 The arrangement of the genital glands is essentially the same in 



