205 ANNALS OF THE CARNEGIE MUSEUM. 
4. Lampsilis nasuta (Say). 
Reported from the Delaware and Schuylkill Rivers, and ‘‘ Little 
Perkiomen Creek’’ (Gabb). Perkiomen Creek is a tributary of the 
Schuylkill in Montgomery County, but there is, as far as I can ascer- 
tain, no stream known now as ‘‘ Little Perkiomen Creek.’’ This 
species has not been reported from the Susquehanna drainage. 
The Carnegie Museum has specimens from the Delaware at Penn’s 
Manor and at Yardley, Bucks County (Ortmann). 
5. Strophitus undulatus (Say). 
The species has been reported from the Schuylkill (Lea) ; Brandy- 
wine Creek, Chester County (Hartman & Michener) ; Crum Creek, 
Delaware County (Lea); Schuylkill Canal, Philadelphia County 
(Schick) ; and from Lancaster County (Bruckhart). 
In the Carnegie Museum it is represented by specimens from the 
following localities: Delaware River, Penn’s Manor and Yardley, 
Bucks County (Ortmann); Little Neshaminy Creek, Grenoble, 
Bucks County (Ortmann) ; Schuylkill Canal, (H. J. Gera), and 
Schuylkill River, Manayunk, Philadelphia County (Ortmann) ; 
Middle Creek, Freeburg, Snyder County (Atkinson) ; West Branch 
Mahantango Creek, Richfield, Juniata County (Atkinson); Cocolamus 
Creek, Cocolamus, and Lost Creek, Mifflintown, Juniata County (At- 
kinson) ; Raystown Branch of the Juniata River, Everett, Bedford 
County (P. E. Nordgren); Beaver Dam Creek, Flinton, Cambria 
County (Atkinson) ; Swartz Run, Ashville, Cambria County (Ort- 
mann); Cush-Cushion Creek, Green Township, Indiana County 
(Atkinson and Ortmann). 
This species is generally small in eastern Pennsylvania, representing 
the typical wxdu/atus. Yet locally it attains considerable size, for 
instance in Little Neshaminy Creek, in Beaver Dam, and in Cush- 
Cushion Creek. In fact specimens from the latter creek (abandoned 
reservoir) are the largest I possess, larger than any from western 
Pennsylvania. According to Simpson, both forms, wadulatus and 
edentulus, are found in the Atlantic drainage, but my material shows 
that large and small individuals cannot be separated as species, be- 
cause they pass gradually into each other. ‘There are small ones from 
Cush-Cushion Creek, which agree perfectly with specimens of the 
same size from other localities farther east. Compare notes under 
this species in the Ohio drainage. 
6. Anodonta cataracta Say. 
