APPENDIX F. SHELLS. 227 



3. • Unio siliquoideus, Barnes. 

 Found in a small creek between Fort Arbuukle and Fort Washita. 



4. Unio l^evissimus, Lea. 



A few detached valves of this species were found on the banks of 

 Otter creek. 



[5. Anodonta imbecilis, Say. 



Abundant and very beautiful, in Beaver creek ; more sparingly in a 

 small creek between Fort Arbuckle and Fort Washita. 



6. Planorbis trivolvis, Say. 



Abundant in many of the streams' from Fort Belknap to the sources 

 of Red river. 



V. Physa gyrina, Say. 

 Beaver creek, Choctaw Nation. 



8. Succinea avara, Say. 

 Otter creek, Choctaw Nation. 



9. Cyclas partumeia, Say. 

 Otter and Beaver creek. 



10. BULIMUS DEALBATA, Say. 



Texas. 



