336 The Molluscan Family Planorbidae 



PLATE 50 



Jaws of Planorbidae 



1. Helisoma tenae calijornicnse F. C. Baker. Shandon, California. 



2. Planorhiila armigera (Say). Muri)hy Creek, near Madison, Wisconsin. 



3. Pkmorbula jenksii (H. F. Carpenter). Unionville, Connecticut. 



4. Porapholyx effusa klamathensis F. C. Baker. Klamath Lake, Oregon. 



5. Porapholyx effusa diagonalis J. Henderson. Crater Lake, Oregon. 



6. Menetus sampsoni (Ancey). Near Stanton, Missouri. 



7. Menetus cooperi caUioglyptus (Vanatta). Vancouver Island, British Columbia. 



8. Promenetus exacuous (Say). Winnebago Lake, Wisconsin. 



9. Menetus dilatatus (Gould). Unionville, Connecticut. 



10. Indoplanorhis exustus (Deshayes). North Shan State, Burma. 



n. Tropicorbis obstructus (Morelet). New Orleans, Louisiana. Superior jaw. 



12. Tropicorbis riisei (Dunker). Puerto Rico. 



13. Australorbis glabratus (Say). Puerto Rico. 



14. Planorbarius corneus (Linn.). Near Warsaw, Poland. 



15. Promenetus umbilicatellus (Cockerell). Wainwright Park, Alberta. 



16. Gyraulus parvus (Say). Winnebago Lake, Wisconsin. 



17. Gyraulus hirsutus (Gould). Lake Nipissing, Ontario, Canada. 



18. Gyraulus deflectus obliquus (DeKay). Taylor Lake, Quebec, Canada. 



19. Gyrauhis vermicrdaris (Gould). Near San Francisco, California. 



20. Armiger crista (Linn.). Wisconsin. 



21. Planorbis planorbis (Linn.). Near Warsaw, Poland. 



22. Gyraidus circumstriatus (Tryon). Wainwright Park, Alberta. 



23. Intha capitis Annandale. Burma. 



24. Segmentina nitida (Muller). Near Warsaw, Poland. 



25. Ayiisus spirorbis (Linn.). Near Warsaw, Poland 



26. Drepanotrema hoffmani F. C. Baker. Puerto Rico. 



27. Drepanotrema lucidum (Pfeiffer). Cuba. 



28. Gyraulus albus (Muller). Near Warsaw, Poland. 



Figures are greatly enlarged. Sizes are disproportionate. 



