372 The Molluscan Family Planorbidae 



PLATE 68 



Radiilae of Planorbidae 



See remarks on plate 53. Line at lower right of plate indicates 25 microns 

 in length for figs. 5-9; lines for figs. 1-4 are 10 microns in length. 



1. Bctthyomphalus contortus (Linn.). Near Warsaw, Poland. 



60, center tooth. 



2. Drepcmotrema lucidum (Pfeiffer). Havana, Cuba. 



50, center tooth; 1-8, lateral teeth; 13, 14, intermediate teeth; 15, marginal tooth. 



3. Drepanotrema anatinum (Orbigny). Puerto Rico. 



50, center tooth; 1-5, lateral teeth; 7, 9, intermediate teeth; 13, marginal tooth. 



4. Drepanotrctiia hoffmani F. C. Baker. Puerto Rico. 



52, center tooth; 1-6, lateral teeth; 8, intermediate tooth; 11-21, marginal teeth. 



5. Australorbis glabratus (Say). Puerto Rico. 



60, center tooth; 1-13, lateral teeth; 14, 15, intermediate teeth; 16-26, marginal 

 teeth. 



6. Tropicorbis riisci (Dunker). Lares, Puerto Rico. 



50, center tooth; 1,. lateral tooth; 5, 6, intermediate teeth; 7-12, marginal teeth. 



7. Tropicorbis obstructus (Morelet). New Orleans, Louisiana. 



60, center tooth; 1-7, lateral teeth; 8, 9, intermediate teeth; 11-14, marginal teeth. 



8. Tropicorbis havane^isis (Pfeiffer). New Orleans, Louisiana. 



55, center tooth; 1, lateral tooth; 6-8, intermediate teeth; 10, 12, marginal teeth. 



9. Gyraulus albus (Midler). Near Warsaw, Poland. 



60, center tooth; 1, 5, 8, lateral teeth; 10. intermediate tooth; 12. 13, marginal 

 teeth. 



