554 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.57. 



beyond the level of the ventral sucker, encroaching on the median 

 field in this neighborhood, and may unite in front of the ventral 

 sucker. Distance from the transverse vitelline ducts to the center 

 of the ventral sucker always somewhat greater than the distance 

 from the latter to the anterior limits of the vitellaria, and may be 

 twice as great. Posteriorly the vitellaria fill up most of the post- 

 testicular zone, crossing the median line, also present between the 

 testes, and may have numerous lobules on the dorsal and ventral 

 sides of the testes. Eggs 36 to 40 [x long by 16 to 22 ^ wide. 



Host. — Lams delawarensis. 



Location. — Intestine. 



Locality collected. — Washington, District of Columbia. 



Type speciTnens. — U.S.N.M. Helminthological Collections No. 2845, 

 collected by Dr. A. Hassall, March, 1897. 



Apophalliis hrevis is very similar to A. muehlingi. It is somewhat 

 smaller, relatively broader posteriorly. The oral sucker is smaller, 

 30 to 50 [JL as compared to 54 [a. The pharynx is also smaller, 20 to 

 28 [J, as compared to 37 [jl. The vitellaria extend farther forward, 

 and encroach upon the median field in front of the ventral sucker, 

 whereas in A. muehlingi as described by Muehling (18986) they do 

 not extend forward of the level of the ventral sucker nor into the 

 median field anteriorly. The eggs are larger, 36 to 40 [jl long in A. 

 bi'evis, 32.4 [JL long in A. muehlingi. Considering these differences it 

 appears that A. hrevis is specially distinct from A. muehlingi^ though 

 they are very similar to one another. 



Genus COTYLOPHALLUS, new genus. 



Generic diagnosis. — Heterophyidae : Prepharynx very short, prac- 

 tically absent. Bifurcation of intestine nearer to ventral sucker than 

 to oral sucker. Intestinal ceca extend into the posterior part of the 

 body, ending in the neighborhood of the level of the posterior border 

 of the right testis. Ventral sucker median, one-third to one-half the 

 body length from the anterior end, opening to the exterior through 

 the genital pore. The genital sinus which opens to the exterior 

 through the genital pore and in which the vas deferens and vagina 

 terminate, is situated immediately in front of the ventral sucker. 

 Prostatic portion of vas deferens well developed, situated posterior 

 and dorsal of, and to the left of, the ventral sucker. Seminal vesicle 

 well developed, forming a U-shaped loop, with its limbs one in front 

 of the other, posterior and dorsal of the ventral sucker, dorsal of the 

 coils of the uterus, base of the U to the right near the right branch 

 of the intestine. Testes near posterior end of body, oval or globular ; 

 right testis obliquely behind the left. Seminal receptacle in front of 

 and to the right of the left testis. Ovary globular or elongated. 



