26 Tin-: naljua's. 



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

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

 only of incremental lines. Height o( shell 5.25; of last whorl 4.0; 

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

 about three whorls. 



THE MOLLTJSCAN FAUNA OF NORTHAMPTON COUNTY, PENNSYLVANIA. 



BY G. W. CAFFREY. 



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

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

 the following list have been found within the county, and nearly all 

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

 explored. 



Helix appressa Say, described by Hartman in " Conchologica 

 Cestrioa " 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 sliell-bearing mollusca, lime- 

 stone being abundant, and the wateis stningly im]>regnated with that 

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

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

 Helicidiz and Pupillidce. 



Ll.MAClUiE. 



Limax maximus L. Bethlehem. 



Limax ayrestis Miiil. Bethlehem. AV. L. King. 



Limax campestris Binn. Bethlehem. 



ZONITIDiK. 



Gastrodonta gularis Say. One specimen in drift on Monocasy 

 Creek. 



Gastrodonta suppressa Say. INIonocasy Creek. 



Zonitoides nitida Miill. Bank of Monocasy Creek. 



VitrcBa cellaria Miill. Rare, West Bethlehem, bank uf Mono<nsy 

 Creek, W. L. King. 



Zonitoides arboreo Say. Common. 



