Proootyla typhtops Kenk , 1935 



90 



Fig. 91 after Kenk (1935), 



A small, slender species, up to 12 mm long and 1.3 mm wide. Head truncate, 

 with straight or slightly convex frontal margin, rounded lateral edges, 

 and an insignificant narrowing behind them. No distinct adhesive organ. 

 Eyeless and white. Testes numerous, predominantly dorsal, extending 

 posteriorly to the region of the pharynx. Vasa deferentia, after passing 

 through the spermiductal vesicles, unite outside the penis bulb to a com- 

 mon sperm duct which is also sinuous and expanded. The penis consists of 

 a large, elongated, muscular bulb and a short, conical papilla. The com- 

 mon vas deferens enters the anterior part of the bulb and continues the 

 entire length of the bulb ventrally to a large, glandular cavity with 

 which it communicates at the base of the papilla. The role of this cavity 

 is probably that of a prostatic gland adding its secretions to the sperm 

 passing through the sperm duct. The wall of the penis bulb has three 

 layers: an outer, thick layer of approximately longitudinal muscle fibers, 

 a thin fibrous layer, and an inner layer of circular muscles. The lumen 

 of the penis papilla, representing the ejaculatory duct, tapers toward the 

 tip of the papilla where it opens into the atrium. The copulatory bursa 

 is typical, sac-shaped, its duct at first rather narrow but gradually 

 widening posteriorly without a histologically differentiated vagina. Ap- 

 parently a subterranean species found in springs and groundwater pools in 

 Virginia (a two-eyed form alleged to be this species has been reported 

 from Florida, but this record needs confirmation) . In the laboratory the 

 species accepts liver and Tubifex as food. Literature: Kenk (1935). 



64 



