322 The Molluscan Family Planorbidae 



PLATE 43 



Pronienetus umbilicatellus (Cockerell) 



From lake southwest of Mott Lake, Wainwright Park, Alberta; collected by 

 Dr. Stiles. Received from the Canadian National Museum. 



L Genitalia dissected and organs separated. 



2. Head showing pseudobranch and pneumostome. 



3. Penial complex opened to show penial gland, verge, diaphragm, etc. 



4. Penial complex in natural position. 



5. Albumen gland from below. 



6. Cross section of prostate and uterus about midway of length. 



7. Portion of genitalia showing union of oviduct and sperm duct, also carrefour. 



8. Cross section of ovotestis. Note developing ova. 



9. Penial gland showing channel-like duct, viewed from above. 



10. Penial gland viewed from the side showing how gland is folded and base attached 



to preputium at lower end. 



11. Section of penial gland. 



12. Termination of \erge showing small fleshy appendage at end. 



Line near figure indicates 1 mm. in length. Figures 5, 6, 7, and 8 have 



same measurements as fig. 1. Figures 9. 10, 11, and 12 



have same measurements as fig. 3. 



