i8o Bryant Walker 



Genus PARAPTERA Ortmann, 1911. 



The type of this genus is U. gracilis Bar. If, as claimed by Frierson and 

 others, this is the Unio fragilis Raf., which the latter in 183 1 made the type 

 of his genus Lasmonos, this name would have priority over Paraptera. 



Frierson (42, p. 6) has suggested that if leptodon Raf. should prove to 

 belong to this genus, Leptodea Raf., of which leptodon is the type, would 

 have to be used. 



Genus OBOVARIA Rafinesque, 1819. 



OnovARiA ciRCULUs (Lea). 



Obliquaria subrofiinda Raf. has been identified as this species by Say 

 and Conrad and the latter adds Obovaria striata Raf. as a synonym. The 

 specimens imder both of these names in the Poulson collection, according 

 to Vanatta (140, p. 552), are this species. If identifiable from the original 

 descriptions, either of Rafinesque's names would have priority. 



Obovaria kllipsis (Lea). 



Conrad has identified Amblema olivaria Raf. as this species and accord- 

 ing to Vanatta (140, p. 553) so also is the shell in the Poulson collection 

 under that name. If identifiable from the original description Rafinesque's 

 name has priority. 



Obovaria i,i;ns (Lea). 



According to Ortmann (79, p. 323) this species is not specifically dis- 

 tinct from O. circulus (Lea). Vanatta (140, p. 552) states that the shell 

 labelled Unio levigata Raf. in the Poulson collection is this species. If iden- 

 tifiable from the original description, levigata would have precedence 



Obovaria retusa (Lam.). 



According to Vanatta (140, p. 552) this is the Obovaria torsa Raf. of the 

 Poulson collection. 



Genus CARUNCULINA Simpson, 1898. 



This group is clearly entitled to generic rank as stated by Ortmann (81, 

 p. 68), who has shown that the type is Unio parvus Bar. and not texasensis 

 Lea. 



Frierson (.|2, p. 7) has identified C. glans (Lea) as the Unio (To.vo- 

 lasma) lividns Raf. and consequently substitutes Toxolasma Raf. for Car- 

 iincnlina Simp. 



Genus LAMPSILIS Rafinesque, 1820. 



Lampsius aIvATa (Say). 



Vanatta (140, p. 552) states that the shell labelled Metaptcra luegaptera 

 Raf. in the Poulson collection is this species. Alata is the type of Proptera 

 Raf. 



