158 THE NAUTILUS. 
Tabor (Stone); Ponds along the Darby Creek Branch of the Read- 
ing R. R. 
Limnea humilis Say. Common in most localities. 
Limnea desidiosa Say. Schuylkill River, common. 
Planorbis bicarinatus Say. Delaware and Schuylkill Rivers; 
Canal at Manayunk, common. 
Planor bis trivolvis Say. Same localities as P. bicarinatus. 
Planorbis deflectus Say. Canal at Manayunk, moderately com- 
mon; Kaighn’s Point. N. J., two specimens. 
Planorbis exacutus Say. Ditch, South Broad Street, uncommon. 
Planorbis dilatatus Gld. Near School Lane, rare; Ponds, South 
Broad Street; Fisher’s Station, Germantown (Stone). 
Planorbis parvusSay. Ditch at Kaighn’s Point, N.J., common ; 
near Strawberry Mansion (Vanatta); Fisher’s Station, German- 
town (Stone) ; Westville, N. J. (Fox). 
Segmentina armigera Say. Westville, N. J., common; ditch at 
Kaighn’s Point, N. J.. common; ponds at Point Breeze (H. A. 
Pilsbry). 
ANCYLIDE. 
Ancylus rivularis Say. Rancocas Creek, N. J., and Schuylkill 
R., near Columbia Avenue Bridge (E. G. Vanatta); Perkiomen 
Creek (Johnson) ; Westville, N. J. (Fox). 
PHYSIDE. 
Physa heterostropha Say. This is the most abundant species, 
being found in almost all streams, ditches and ponds of this vicinity. 
Physa heterostropha ancillaria Say. Delaware and Schuylkill 
Rivers. The specimens found show all the stages between hetero- 
stropha and ancillaria ; Westville, N. J. (Fox). 
Aplexa hypnorum L. Glen Riddle, Del. Co.; ditch at Kaighn’s 
Point, N. J., uncommon. This is probably the extreme southern 
limit of this species. 
VALVATIDE. 
Valvata tricarinata Say. Schuylkill River, uncommon; canal at 
Manayunk, common. (Typical locality.) 
Valvata bicarinata Lea. Same locality as the preceding; West- 
ville, N. J. (Fox). 
AMNICOLIDE. 
Amnicola limosa Say. Canal at Manayunk, common ; Westville, 
N.J.; Delaware River, below-Gloucester. Typical locality. 
