189I.] WALTON MOLLUSCA OF MONROE COUNTY. 15 



Dr. Isaac Lea in his great work on the Unionidge in thirteen 

 folio volumes, gives elaborate lithographic figures of the species. 

 Some of our local Unios are finely illustrated in color by DeKay in 

 his "Mollusca of New York State." 



Family UNIONIDGE. 



Unio alatus, Say. Erie canal. 

 My a alata, Wood. 

 Lymnadia alata, Sowb. 

 Metaptera alata, Stimp. 

 Unio cariosus, Say. Erie canal. 

 Unio ovata, Val. 

 " oratiis, Con. 

 Unio complanatus, Sol. Genesee river. 

 Mya purpurea, Eaton. 

 Unio purpureus. Say. 

 " violaceus, Speng. 

 " purpurascens. Lam. 

 " Georgina, Lam. 

 " fluviaiilis. Green. 

 " tortuosus, Sowb. 

 Unio gracilis, Bar. Erie canal. 

 Unio planus. Bar. 

 " frag His, Swain. 

 Unio gibbosus, Bar. Erie canal. 



Unio niucronatus. Bar. 

 " nasuta. Lam. 

 " di la tat us, Con. 

 Unio iris, Lea. Erie canal. 



Unio subrostratus, Say. 

 " nebulosus. Con. 

 *Unio novi-eboraci, Lea. Erie canal. 



Unio opalinus, Anth. 

 Unio nasutus. Say. Erie canal. 

 Unio rostratus, Val. 

 Mya 7iasuta, Wood. 



* This and the preceding are thought to be male and female of the same species. 



