Lingual Dentition in Physa. 257 



Fig. 5. Lingual dentition of Gceotis. One central tooth with adjacent 

 laterals. 



6. Same as last, but more enlarged. An extreme marginal tooth 



in profile. 



7. Same as 5. An extreme marginal tooth. 



8. Amphibulimcf patula (see p. 225.) The jaw folded as it appears 



on the microscope slide, the position taken from its extreme 

 tenuity. 



9. Physa sp. indet. Shell. Jaw and Lingual dentition. Figs. 



2-4. 



[Printed at the Salem Press. 



