1 68 Bryant Wai,ke;r 



QuADRULA rURi'viANA (Lamarck). 



Lamarck in his original description refers to the figure in the Encyc. 

 Meth., pi. 248, fig. 7, but the reference was overlooked by Simpson in his 

 Synopsis, but was supplied in the Desc. Catalogue. The species is the form 

 commonly called plicata Say by collectors and is characterized by its prom- 

 inent beaks. It is quite different from plicata Say from Lake Erie. 



QuADRui^A RARiPUCATA (Lamarck). 



This species, which has been referred to plicata Say by Simpson and 

 authors generally, is neither typical peruviana (Lam.) nor typical plicata 

 (Say). The type which is still preserved in the Museum at Geneva, Switzer- 

 land, is the Ohio River form, which has commonly passed as plicata (Say), 

 and is sufficiently distinct to have varietal rank at least. There is some 

 reason to believe that Say's plicata is an off-shoot from this race rather than 

 of iindiilata Bar. as has been suggested by Ortmann (79, p. 246). It is also 

 possible that it rather than undulata should be considered the costata Raf. 



QUADRULA PLICATA (Say). 



As stated 'by Ortmann (79, p. 246) the type of this species came from 

 Lake Erie and is undoubtedly the form described by Lea as Unio hippopcrus. 

 It has been referred to undulata Bar. by Ortmann (1, c), but there is appar- 

 ently some ground for considering it as more closely allied to rariplicata 

 (Lam.). Pending the settlement of this question, it would seem better to 

 keep it separate from either. 



QuADRULA PLENA (Lea). 



According to Ortmann (78, p. 117) this is probably only a form of 

 obliqua (Lam.). Vanatta states (140, p. 558) that the Obovaria cordata 

 Raf. of the Poulson collection is this species. If identifiable from the orig- 

 inal description, Rafinesque's name would have priority. 



QuADRULA PUSTULATA (Lea). 



According to Vanatta (140, p. 557) the Obliquaria nodulata Raf. of the 

 Poulson collection is this species. If identifiable from the original descrip- 

 tion, nodulata would have precedence. 



QuADRULA PUSTULOSA (Lea). 



According to Vanatta (140, p. 556) the Obliquaria retusa Raf. of the 

 Poulson collection is "probably" this species. The specific name is not pre- 

 occupied by Unio retusa Lam. and, if identifiable from the original descrip- 

 tion, Rafinesque's name would have priority. 



Utterback (135, p. 131) has suggested that the species should be known 

 as bullata Raf., but see next note. 



