46-4 Systematic Paleontology 



EXILIA OEETACEA 11. Sp. 



Plate XIV, Fig. 13 



Description. — Shell very small and slender; whorls probably not less 

 than ten in a perfect individual, very broadly convex, increasing very 

 slowly in size ; body whorl rather abruptly constricted at the base into a 

 very slender canal; external surface axially and spirally sculptured, the 

 axial sculpture dominant, particularly upon the later whorls; axials 

 rather irregular, feebly arcuate upon the whorls of the spire, sinuous upon 

 the body, persistent from suture to suture upon the whorls of the spire, 

 abruptly evanescent on the body before reaching the base, fifteen or six- 

 teen in number on the whorls of the spire, nine or ten on the body ; entire 

 surface overridden from apex to pillar with very fine and crowded con- 

 centric strias, eight on the whorls of the spire, double that number on the 

 body exclusive of the base and the pillar ; characters of aperture not known. 



Dimensions. — Altitude 10 mm., maximum diameter 3.7 mm. 



The affinities of this small species are rather doubtful, but the outline 

 and characters of the sculpture seem to justify its reference to Exilia. 

 Exilia has been reported from the Maestricht beds, but never before from 

 the Cretaceous of this continent. 



Occurrence. — Monmouth Formation. Brightseat, Prince George's 

 County. 



Collection. — Maryland Geological Survey. 



Family PURPUR1DAE 



Genus MOREA Conrad 



[Jour. Acad. Nat. Sci., Phila., 2d ser., vol. iv, 1860, p. 290] 



Type. — Morea cancellaria Conrad. 



"Short-elliptical; aperture much longer than spire; columella reflexed, 

 concave, with a prominent, acute fold at base." — Conrad, 1860. 



Shell heavy, ovate in outline. Whorls not very numerous, flattened, 

 scalariform. External sculpture vigorous, dominantly spiral, aperture 

 broadly lenticular, a little more than half as high as the entire shell, outer 

 lip heavy, inner lip reinforced, narrowly reflected, bearing a single rather 



