76 Trans. Acad. Sci. of St. Louis. 



10. Alasmodonta deltoidea Lea. Erie Canal. 



11. Alasmodonta rugosa Barnes. 

 Station 10. Typical and of good size. 



12. Alasmodonta press a Lea. 



Station 10. This species is said to be common in the upper 

 Genesee River, but the writer obtained only one specimen 



and that was both a deformed 



and pathologic individual of 



small size (length 49; breadth 



18; height 29 mill.). The 



whole shell is much shorter 



and more stumpy than the 



typical form and there is a 



a. pressa lea. peculiar bulge at the posterior 



pathologic specimen. en( j # The teeth are very long 



and very thin. The accompanying cut is an outline figure. 



*13. Alasmodonta undulata Say. (Walton's list). 



Genus Strophitus Rafinesque. 1820. 



14. Strophitus edentulus Say. 

 TJnio ferruginea Lea, Walton's list. 



Station 12. One specimen found. (Long Pond and Gen- 

 esee River, Walton's list.) 



Genus Unio Retzius. 1788. 

 *15. Unio gibbosus Barnes. Erie Canal. 



Genus Anodontopsis Simpson. 1898. 



*16. Anodontopsis subcylindraceus Lea. Irondequoit 

 Creek. 



*17. Anodontopsis ferussacianus Lea. Erie Canal. 



Genus Quadrula (Rafinesque) Agassiz. 1852. 



18. Quadrula rubiginosa Lea. 

 Station 10. Common, and showing no little variation in 

 relative lengths and heights. 



