3 18 NEW YORK STATE MUSEUM 



Dimensions. A specimen of average size has a hight of 13 mm and a 

 diameter of body whorl of 1 1 mm. 



Habitat. Genesee province ; Naples subprovince. In the shales 

 about Naples, particularly in a thin crinoidal layer near the base of Hatch 

 hill ; in the concretions on Honeoye lake. The species also occurs in a 

 nodular layer at the base of the Cashaqua shales at Lodi falls, Seneca co., 

 at Bennettsburg and Beaver Dams, Schuyler co. 



Pleurotomaria itylus sp. nov. 



Plate 19, fig 31, 32 



Shell of medium or regularly large size, spire short, whorls four to 

 five (?), overlapped almost but not quite to the slit band ; surface gently and 

 regularly sloping ; without angulation ; slit band narrow. Upper surface of 

 whorls with numerous fine elevated concentric lines (probably more than 

 100 for each whorl) at quite regular intervals with smooth interspaces. 

 These slope backward to the periphery and are crossed by several (six to 

 eight) obscure revolving lines, at the intersection with which but low eleva- 

 tions are found. Below the slit band only the concentric lines are apparent. 

 This style of ornament approaches somewhat that of P. itys Hall of the 

 Hamilton fauna, in which the intersection of numerous revolving and con- 

 centric lines produces a tubercled exterior. In P. itylus the texture is 

 finer, and the revolving lines almost suppressed. 



Dimensions. The single specimen observed has a hight and width of 

 14 mm. 



Habitat. Genesee province ; Chautauqua subprovince. In the soft 

 shales of Walnut creek, Forestville. 



Pleurotomaria ciliata sp. nov. 



Plate 20, fig. 8-14 



Shell quite small, spire short, volutions five. Whorls rendered step- 

 shaped by the prominence of the slit band, to the base of which overlap 

 occurs except on the final whorl, which may be more loosely wound. Slit 

 band relatively broad with sharp, angular, elevated, thin edges and slightly 



