444 The Molluscau Family Planorbidae 



PLATE 104 



Shells of Planorbidae 



1-3. Heliscmici duryi (Wetherby). Kissimmee River, Florida. \'ariation toward variety 

 normale. U.S.N.M., 168921. 



4-7. HcUsoma duryi (Wetherby). Near West Palm Beach, Palm Beach Co., Florida. 

 Variation toward variety normale. M.C.Z., 45103. 



8-16. Helisoma duryi normale Pilsbry. One mile north of Oil well, Pinecrest, Ever- 

 glades, Florida. U.I., Z34637. 



17. Helisoma duryi normale Pilsbry. Canal west of Boynton, Palm Beach Co., Florida. 

 Malleated base. M.C.Z., 76659. 



18-22. Helisoma duryi normale Pilsbry. Magnolia, Florida. M.C.Z., 87505. 



All figures are enlarged about 1V> diameters 



