26 THK NAUTILUS. 



peripheral cord, which is covered by the advancing whorl; body 

 color crimson; faint spiral striae on the flattened base; axial sculpture 

 only of incremental lines. Height of shell -V^o; ot h.st whorl 4.0; 

 max. diameter 6.0 mm. Operculum as usual in the genus, with 

 about three whorls. 



THE MOLLUSCAN FAUNA OF NOBTHAMPTON COUNTY, PENNSYLVANIA. 



BY G. W. CAFFREY. 



So far as is known to the writer no list of the mollusca oi' this 

 county has been published up to this time. The species named in 

 the following list have been found within the count} 7 , and nearly all 

 occur in the vicinity of Bethlehem, as well a* in other localities 

 explored. 



Helix appressa Say, described by Hartman in " Conchologica 

 Cestrica " as occurring "under flat stones on the Lehigh River," 

 has not been found by the writer, though diligently sought along that 

 stream from Bethlehem to its confluence with the Delaware River at 

 Easton. 



The physical conditions in the Lehigh Valley and adjacent lands 

 are favorable to the development of the shell-bearing mollusca, lime- 

 stone being abundant, and the wateis strongly impregnated with that 

 mineral. The limestone cliffs, old quarries and abandoned lime- 

 kilns found on nearly every farm, afford good collecting ground for 

 Helicidtz and Pupil/idee. 



LlMAClDJG. 



Umax maximus L. Bethlehem. 



Limax agrestis Miil). Bethlehem, W. L. King. 



Limax campestris Binn. Bethlehem. 



ZONITIU.E. 



Gastrodot/ta ynlaris Say. One specimen in drift on Monocasy 

 Creek. 



Gastrodonta suppressa Say. Monocasy Creek. 



Zonitoides nitida Mull. Bank of Monocasy Creek. 



Vitraa cellaria Mull. Rare, West Bethlehem, bank of Monocasy 

 Creek, W. L. King. 



Zonitoides arborea Say. Common. 



