238 The Molluscan Family Plauorbidae 



PLATE 1 



Planorbis planorbis (Linn.) 

 From a pond 25 miles southeast of Warsaw, Poland; from A. Jankowski. 



1. Entire genital system spread out. The dark spaces are folds in the anatomical 



preparation. 



2. Penial complex with muscles. 



3. Head and foot showing form of pseudobranch. 



4. Vertical section through penial complex to show small size of verge. 



5. Section through verge and vas deferens. 



6. Junction of oviduct and vas deferens to form ovisperm duct and connection with 



albumen gland and carrefour. 



7. Section through prostate, oviduct, and vas deferens showing a prostate canal sepa- 



rated from the vas deferens. 



8. Section through ovotestis. 



9. Section through o\'otestis showing di\'erticula embedded in the liver cells. 



Line near figure indicates 1 mm. in length 



