248 The Molluscan Family Planorbidae 



PLATE 6 



Anisus vortex and Anisus spirorbis 



1-4,6. Anisufi vortex (Linn.). From stream in meadow in Jabtonna. 18 km. north- 

 east of Warsaw, Poland; collected by A. Jankowski. 



1. Penial complex showing long and narrow vergic sac. 



2. Stylet, drj' and somewhat crushed. 



3. Section through prostate and sperm canal showing two ducts. 



4. Section through upper portion or preputium and vergic sac, showing papiUa in 



preputium, stylet and outlet of sperm canal at the side of the verge. 



6. Pseudobranch showing relationship to rectum. 



5,7-13. Aiiisus spirorbis (Linn.). From a trench in Struga, 12 km. northeast of War- 

 saw, Poland; collected by A. Jankowski. 



5. St5det at end of verge with outlet of sperm canal at side of verge. 



7. Two diverticula of ovotestis. 



8. Cross section through prostate and o\ iduct. 



9. Albumen gland, upper part. 



10. Penial complex in vertical section showing stylet, muscular i)apilla, and jiilasters. 



11. Foot, pseudobranch, and jmeumostome. 



12. Entire genitalia dissected and separated. 



13. Penial complex of specimen with vergic sac shortened and club-shaped. 



Line near figure indicates 1 mm. in length. Figures 2 and 5 

 are greatly enlarged. 



