MOLLUSCA. 677 



ture broadly ovate or subcircular, the inner margin straightened 

 somewhat, conforming to the slope of the umbilicus. Surface of 

 the shell marked by a series of moderately close, elevated, lamel- 

 lose, transverse ridges or varices, which are directed rather 

 strongly backward in their passage from above to the lower mar- 

 gin, and are less conspicuous on the flattened space bordering 

 the umbilicus, within the umbilicus they are faintly shown. There 

 are also fine transverse rigid lines parallel to the varices, occupy- 

 ing the ridges and intervening- spaces, also rather strong, 

 rounded, wiry spiral lines covering the entire surface of the shell, 

 which are perceptibly directed upward in crossing the varices. 

 This gives the surface of the shell a very beautifully cancellated 

 structure, easily perceptible to the unaided eye." (Whitfield.) 



Remarks. This species has not been met with in the recent 

 collections of the Survey. Whitfield described the genus Cavos- 

 cala with this species as the type and only representative, it being 

 characterized especially by the wide umbilicus and the carinated 

 suture with the under side of the outer volution flat and smooth, 

 the smooth area being bounded by the margin of the umbilicus 

 within and the sutural carina without. 



Formation and locality. Vincentown limesand, Timber Creek 

 (Whitfield). 



Geographic distribution. New Jersey. 



Super-family TAENIOGLOSSA. 

 Family NATICIDAE. 



Genus LUNATIA Gray. 



Lunatia halli Gabb. 

 Plate LXXVL, Figs. 9-19. 



1860. Lunatia Halli Gabb, Jour. Acad. Nat. Sci. Phil., 2nd ser., 



vol. 4, p. 391, pi. 68, fig. ii. 

 1864. Lunatia Halli Meek, Check List Inv. Foss N. A., Cret. 



and Jur., p. 20. 

 1868. Lunatia Halli Con., Cook's Geol. N. J., p. 729. 



