302 The Molluscan Family Planorhidae 



PLATE 33 



Helisoma 



1-7. Helisoma duryi eiidiscus Pilsbiy. From Silver Springs, Florida; collected by T. 

 Van Hyning. 



1. Penial complex showing swollen duct of penial gland and position of verge in 



vergic sac. 



2. Penial complex from exterior with penial gland duct uncoiled. 



3. Penial gland in section showing the long, shallow cup. 



4. Exterior view of penial gland. 



5. Penial complex with preputium pushed upward. 



6. Penial complex of immature specimen, shell 6.5 mm. in diameter. 



7. A very wide example of penial complex. 



8-10, 12, 16-19. Helisoma duryi normale Pilsbry. 



8. Penial complex. From near Paines Prairie, Gainesville, Florida; collected by 



T. Van Hyning. 



9. Penial complex with swollen preputium. From Santa Fe River, High Springs, 



Alachua Co., Florida; collected by T. Van Hyning. 



10. Penial gland in section. Same locality as fig. 9. 



12. Penial complex. Variation in form. From Tamiami Trail, 40 miles west of 



Miami, Florida; collected by W. F. Shay. 



16. Head and neck with penial gland protruding from male opening. Same locality 



as fig. 12. 



17. Penial complex. A normal form showing short penial gland duct. Same 



locality as fig. 12. 



18. Penial complex. A very wide example. Same locality as fig. 12. 



19. Penial gland of half-grown specimen. From near Gainesville, Florida. 



11,13,14. Helisoma duryi (Wetherby), near typical form. Same locality as fig. 12. 



11. Penial gland, partly contracted. 



13. Penial complex with penial gland protruding from male opening. 



14. Penial complex of normal specimen. 



15. Helisoma duryi normale Pilsbry, varying toward intercalare (Pilsbry). 



15. Genitalia dissected and organs separated. From canal at Boynton, Florida; 



collected by W. F. Shay. 



Line near figure indicates 1 mm. in length 



