58 ILLINOIS BIOLOGICAL MONOGRAPHS [276 



opening terminal, oral sucker small, pharynx weak but distinct. Esophagus 

 very short; intestinal ceca simple, ending blindly in the extreme posterior 

 of the body. Genital pore inconspicuous, median, ventral to the pharynx. 

 Ovary situated in the anterior one-fourth of the body, lateral, usually 

 intracecal; shell gland smaller than the ovary and posterior to that organ. 

 Receptaculum seminis present, usually about two-thirds as large as the 

 ovary. Laurer's canal absent. Uterus, except for the four longitudinal 

 loops, coiled around the intestinal crura from the level of the ovary to the 

 posterior end of the animal. Vitelline gland a coarse, compact U-shaped, 

 closed tubular structure, dorsal to the intestine. Testis U-shaped, closed 

 portion cephalad, about one-fourth the body length from the anterior 

 end. The tubular, irregularly lobed testicular mass extends caudad to a 

 level about one-eight the body length from the posterior end. Protrusible, 

 non-muscular cirrus present. Excretory pore median, anterior, dorsal to 

 the pharynx. Eggs large, ovoid, thin shelled, containing fully developed 

 miracidia in the metraterm. 



The anatomy of this form is well described by MacCallum (1902) and 

 Barker and Parsons (1914, 1917), and with the additions and corrections 

 of Stunkard (1919) calls for no further anatomical discussion here. 



The writer has been given an opportunity to examine the type specimen 

 of this species deposited in the United States National Museum and can 

 verify the statements of Stunkard on the specific identity of the two species. 



MacCallum reported the original material from Chelydra serpentina 

 taken in the Grand river at Dunville, Ontario, Canada. Barker and 

 Parsons (1914) report from Chrysemys marginata taken in Lake Emily, 

 Minnesota, and the Mississippi river and later (1917) in the same host 

 taken in the Mississippi river near Fairport, Iowa. At this time they call 

 attention to the distribution in Illinois. 



Ward (1917) reports this species from " various turtles" taken in Michi- 

 gan, Indiana, Illinois and Nebraska. Stunkard (1919) collected this species 

 from Chelydra serpentina taken in Illinois, Ohio, North Carolina and Texas; 

 in Chrysemys marginata taken in Iowa, Illinois, Missouri and Kentucky; 

 in Pseudemys elegans and Malacoclemmys geographicus in Illinois; Aro- 

 mochelys odoratus and Kinosternum pennsyhanicum in North Carolina. 

 The specimen listed by Stiles and Hassall (1894:253) as "Monostomasp. 

 Chelonia gen. sp. (bronchi) Illinois-Forbes-Leidy" belongs here. 



The writer has found this species in Chelydra serpentina and Chrysemys 

 marginata taken in the drainage ditch at Urbana, Illinois; in Chrysemys 

 marginata taken in the Mississippi river near Fairport, Iowa; in Graptemys 

 geographicus taken near Chicago, Illinois; in Chelydra serpentina and 

 Chrysemys marginata taken in Minnesota and in Kinosternum pennsylvani- 

 cum, Kinosternon odoratus, and Chrysemys pida, a new host, taken in North 

 Carolina. 



