264 The Molluscan Family Plauorbidae 



PLATE 14 



Gyraulus albus (Miiller) 

 From pond in Krolikania, a suburb of Warsaw, Poland; from A. Jankowski. 



1. Penial complex sectioned to show verge, stylet, etc. 



2. Penial complex, external view. 



3. Fore part of animal showing pseudobranch and pneumostome. 



4. Fore part of animal showing pseudobranch, pneumostome, and venation of some 



of these organs. 



5. Albumen gland from below. 



6. Portion of genitalia showing attachments of albumen gland duct, oviduct, sperm 



duct, and general relationship of these and other organs. 



7. Genitalia dissected and organs separated. 



8. Stylet at end of verge with sperm canal outlet at side of verge. 



9. Section of prostate showing distinct canals for prostate and sperm duct. Three 



diverticula are shown. 



10. Section through ovotestis near front end. 



11. Distal end of ovotestis showing grouping of diverticula. 



Line near figure indicates 1 mm. in length. Line at lower right corner 



of plate is for figs. 5, 6, 7. 9, 10, and 11. Figure 8 line is 



one-sixth of 1 mm. in length. 



