208 Annals of the Carnegie Museum. 



Huntingdon County (Ortmann) ; Raystown Branch, Everett, Bedford 

 County (P. E. Nordgren) ; Raystown Branch, Bedford, Bedford 

 County (A. Koenig ) ; Driftwood Branch of the Sinnamahoning 

 Creek, Driftwood, Cameron County (Ortmann). 



These represent generally the eastern variety {I'firicosa) of this 

 species ; yet there are, among a fine set collected by the writer at Ar- 

 denheim, several large individuals, which approach in the greater de- 

 velbpment of the anterior part of the shell and the sharper posterior 

 ridge, and more distinct truncation of the posterior end. the western 

 form (see above). 



12. Margaritana margaritifera (Linnsus). 



Lea (Observ., II, p. 56) records this species from Crum Creek, 

 Delaware County, and Hartman & Michener from White Clay Creek, 

 Chester County. Both records are very doubtful, and have not been 

 confirmed. Lea (Observ., VII, p. 225) says that it goes as far south 

 as middle Pennsylvania. The only positive record we possess is from 

 Still Creek, Quakake, Schuylkill County (Conner, Nautilus, 18, 1904, 

 p. 91). I have seen specimens from this locality in the Philadelphia 

 Academy. Yet the trouble is, that I was unable to locate " Still 

 Creek" on the topographical survey map (sheets Hazleton and Ma- 

 hanoy), and also the place Quakake. There is a Quakake Junction in 

 Schuylkill County and a Quakake Creek in Carbon County. 



In the Carnegie Museum this species is not represented from Penn- 

 sylvania. 



13. Unio complanatus (Dillwyn). 



Many records are at hand from Philadelphia, Delaware, Chester, and 

 Lancaster Counties, but none to the west of these. 



In the Carnegie Museum the species is represented from the follow- 

 ing places : Little Neshaminy Creek, Grenoble, Bucks County (Ort- 

 mann); Common Creek, Tullytown, Bucks County (Ortmann); 

 Delaware River, Penn's Manor and Yardley, Bucks County (Ortmann); 

 Schuylkill Canal, Manayunk, Philadelphia County (H. J. Gera); 

 Susquehanna River, York Furnace, York County (Ortmann); Susque- 

 hanna River and Sherman's Creek, Duncannon, Perry County (Ort- 

 mann); Juniata River, Juniata Bridge, Perry County (Ortmann); 

 Pennsylvania Canal and Lost Creek, Mifflintovvn, Juniata County 

 (Atkinson); Cocolamus Creek, Cocolamus, Juniata County (Atkin- 

 son); Juniata River, Lewistown, Mifflin County (Ortmann); Rays- 

 town Branch of the Juniata River, Ardenheim, Huntingdon County 



