434 Systematic Paleontology 



the folds are narrow and distinct, and very slightly bent backward in the 

 middle of their length in their passage across the volution, but not inter- 

 rupted perceptibly at the line separating the band from the body of the 

 volution, and become obsolete on the rostrated part of the last one. 

 Besides the vertical folds, the entire shell is marked by sharp, closely 

 arranged spiral lines, which are finer and more numerous on the upper 

 part, becoming more distant and stronger below, especially on the lower 

 part of the last volution, where they seem to have alternated with finer 

 intermediate striae. This latter feature may be only apparent, however, 

 as the condition of the specimens is not such as entirely to establish this 

 feature as a character of the shell. The crossing of the vertical folds by 

 the spiral stria? in the upper volutions produced a very decided and beau- 

 tifully cancellated structure." — -Whitfield, 1892. 



Type Locality. — Freehold, New Jersey. 



Yulpecula reileyi Whitfield is so poorly preserved both in the New 

 Jersey and in the Maryland material that the diagnostic generic features 

 of the aperture, the number and disposition of the columellar folds and 

 the characters of the outer lip, cannot be determined. In the Maryland 

 material the columellar plications are, apparently, three in number. 



Occurrence. — Monmouth Formation. Brightseat, and Brooks estate 

 near Seat Pleasant, Prince George's County. 



Collections. — Maryland Geological Survey, Columbia University. 



Outside Distribution. — Monmouth Formation. Navesink marl, New 

 Jersey. 



Family VAS1DAE Adams 



Genus XANCUS Bolten 

 [Mus. Boltenianum, 1798, p. 134] 



Type. — Voluta pyrum Gmelin. 



Shell moderately heavy, pear-shaped or fusiform ; protoconch papillate. 

 Spire varying in relative altitude from more than one-half to less than 

 one-third that of the entire shell. Whorls rather numerous, flattened or 

 angulated at the periphery. External sculpture dominantly axial, fre- 



Etymology: Modification of East Indian vernacular name. 



