70 ILLINOIS BIOLOGICAL MONOGRAPHS [350 



structure comprises twelve concentric rings or lamellae of muscles. It 

 is 0.2 mm. long by 0.14 mm. wide in the toto specimen and 0.314 mm. in 

 depth in the sectioned individual. The diverticula extend posteriad al- 

 most to the cephalic margin of the acetabulum. In sections they are oval, 

 and flattened laterally. In the intestine of the sectioned worm there are 

 masses of small nuclei, possibly from the epithelial lining of the cloaca 

 of the host. 



Male Reproductive Organs. — The testes are oval, in the toto speci- 

 men they are 0.17 mm. long by 0.17 mm. wide, and in the sectioned worm 

 0.17 mm. wide by 0.29 mm. thick. They are situated one in front of the 

 other in the median line and in the ventral part of the body. They are 

 close together, separated only by a thin fibrous sheet. The vasa efferen- 

 tia arise at the dorsal margins of the testes; the duct from the caudal 

 testis pass anteriad and anterior to the cephalic testis unites with the 

 duct from this latter testis. The vas deferens immediately expands into 

 a long much-coiled seminal vesicle which passes anteriad and into the 

 cirrus sac (Fig. 69). Inside the cirrus sac the tube continues in large 

 coils; the terminal part is surrounded by the cells of the prostate gland 

 and opens to the surface thru a short hermaphroditic duct. There is a 

 small genital papilla (Fig. 71). 



Female Reproductive Organs. — The ovary is oval; in the toto speci- 

 men it is 0.098 mm. long and 0.088 mm. wide, and in the sectioned worm 

 it is 0.95 mm. wide and 0.134 mm. thick. It is median in position and 

 situated midway between anterior and posterior ends of the body. The 

 oviduct arises at the dorsal posterior margin and passes dorsad and pos- 

 teriad into Mehlis' gland. This gland is large and well developed. 

 Here Laurer's canal is given off and passes in short coils to the dorsal 

 surface. Just after the origin of Laurer's canal a short common vitelline 

 duct opens into the ootype and the oviduct passes ventrad. It expands 

 to form the initial part of the uterus, turns anteriad, and is filled with 

 masses of spermatoza. The expanded portion of the uterus extends an- 

 teriad half the distance to the caudal testis and then the tube contracts, 

 passes dorsad and in a winding course over the testes. Anterior to the 

 testes it turns ventrad and enters the hermaphroditic duct on the pos- 

 terior ventral side. The vitellaria extend from the region of the testes 

 to the caudal ends of the digestive ceca and consist of scattered lobes, 

 mostly ventral in position. Anteriorly they are extracecal but behind 

 the ovary they are intracecal as well. 



No eggs were present in any of the specimens. 



The genital pore is in the midventral line, just posteror to the bi- 

 furcation of the alimentary tract. There is a genital sinus but no geni- 

 tal sucker. 



