404 The MoUuscan Family Plauorbidae 



PLATE 84 



Shells of Plauorbidae 



1. Helisoma anceps (Menke). Immature shell. XSVj. 



2. Helisoma anceps percarinatum (Walker). Immature shell. XZYz- 



3. Helisoma anceps portagense (F. C. Baker). Immature shell. XS^/^. 



4. Helisoma anceps royalense (Walker). Immature shell. XS^/^. 



5. Helisoma anceps sayi F. C. Baker. Immature shell. XS^/^. 



6-8. Helisoma anceps jordanense (Winslow). Lake Charlevoix, NE of Jordan, Charle- 

 voix Co., Michigan. Topotypes. U.M., 61589. 

 9. Helisoma anceps royalense (Walker). Isle Royale, Michigan. Cotype. B. Walker. 



B995. 

 10-12. Helisoma anceps rushi F. C. Baker. Toad Island, Georgian Bay, Ontario. 



lOholotype; 11-12 paratypes. U.I., Z25239. 

 13,14. HeUsoma rmceps royalense (Walker). St. Joseph Lake, Ontario. U.I., Z30853. 

 15-17. Helisoma anceps royalense (Walker). Bamiji Lake, Ontario. U.I., Z30844. 

 18-20. Helisoma eucosmius (Bartsch). Types. Bull. U.S.N.M., 33, plate 57, figs. 1-3. 



X4. 

 21. Helisoma eucosmius (Bartsch). Greenfield Pond, North Carolina. Paratype. 



U.S.N.M., 193890. XSV-i- 

 22-24. HeUsoma eucosmius vauyhani (Bartsch). Types. Bull. U.S.N.M., 33, plate 57, 



figs. 4-6. X4. 

 25. Helisoma eucosmius vaughani (Bartsch). Burke's Place, Louisiana. Paratype. 



U.S.N.M., 125719. XSi;.. 

 26-28. Helisoma anceps idahoense F. C. Baker. Pend (Jreille River, Sand Point, 



Idaho. Holotype. B1863. 



All figures are enlarged about twice excepting those otherwise listed 



