550 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.57. 



front of testes on right of median line. Seminal receptacle near 

 median line between ovary and testes. Vitellaria purely lateral in 

 position except at the level of the genital sucker, where they bend in 

 on each side and form a complete arch in front of the ventral sucker, 

 the anterior limits of their distribution being in the immediate neigh- 

 borhood of the level of the ventral sucker. Uterus arranged in three 

 fairly regular transverse convolutions, laterally not extending much 

 beyond the intestinal branches. Eggs numerous, light brown in 

 color, 31 to 36 [i long by 16 to 19 \k wide. 



Host. — Totanus calidris. 



Location. — Intestine. 



Locality collected. — Great Britain. 



Genus PARACOENOGONIMUS Katsurada, 1914. 



GeneHc diagnosis. — Heterophyidae : In characters thus far de- 

 scribed resembles genus Cryptocotyle except that the egg is very 

 large, over 100 [x long. Immature stage (encysted cercaria) in mus- 

 cles of fresh-water fishes; adults presumably in intestine of fish- 

 eating animals, young adults having been reared in mice fed with 

 cercariae. 



Type species. — Para^oenogonimus ovatus Katsurada, 1914. 



PAKACOENOGONIMUS OVATUS Katsurada. 1914. 



Figs. 18, 19. 



1914. Paracoenogonimtis ovatus Katsurada, 1914, pp. 313, 314, figs. 7, 8, 9, 

 12, 13 (immature stage in muscles of fishes, Plotzen, Brachsen, 

 Barben, Plinten, Ulvelei, etc.; Rivers Elbe and Alster, Germany; 

 young adults in intestines of experimentally infected mice). 



Specific diagnosis. — Paracoenogonimus: Young individual from 

 intestine of mouse, four days after feeding immature stages in the 

 muscles of "Alsterplotze," measured 0.522 mm. long, 0.378 mm. 

 broad ; oval in shape. Pharynx close behind the oral sucker ; esoph- 

 agus short. Bifurcation of intestine at the beginning of the sec- 

 ond fourth of the body. Intestinal ceca extend into the posterior 

 portion of the body. Ventral sucker about midway of the body, 

 considerably smaller than the oral sucker; musculature very weakly 

 developed. Genital pore median, a short distance behind the ventral 

 sucker and surrounded by a genital sucker. Testes irregularly oval 

 near posterior end of body; right testis obliquely behind the left. 

 Vitellaria in lateral fields extending from the level of the ventral 

 sucker into the post-testicular region. A single Qgg present, 116 [i 

 long by 76 [jl wide ; brownish-yellow in color. 



Immature stage (encysted cercaria). — Cysts rounded; 324 [jl in 

 diameter, wall of cyst 28.8 [i tliick (Elbplotze) : 317 (ji by 306 (x in 



