364 The MoUuscan Family Planorbidae 



PLATE 64 



Radulae of Helisoma 



See remarks on plate 53. Line at lower right of plate 

 indicates 25 microns in length. 



L Helisoma scalare (Jay). Lake Butler, Florida. 



89, center tooth; 1-8, lateral teeth; 9-11, intermediate teeth; 12-21, marginal teeth. 



2. Helisoma scalare (Jay). Lake Butler, Florida. 



86, center tooth of another specimen; 1-6, lateral teeth. 



3. Helisoma duryi normale Pilsbry. Tamiami Trail, 40 miles west of Miami, Florida. 



110, center tooth; 1-11, lateral teeth; 12, intermediate tooth; 13-29, marginal 

 teeth. 12, lower right, 12th tooth (marginal) in another row of teeth. 



4. Helisoma duryi normale Pilsbry. Paines Prairie, Florida. 



55, center tooth ; 1-9, lateral teeth; 10, intermediate tooth; 11-26, marginal teeth. 

 140, center tooth; 1-10, lateral teeth; 11, intermediate tooth; 12-20, marginal 

 teeth. 



