MARYLAND GEOLOGICAL SURVEY 211 



prominent lirse disposed somewhat in pairs ; canal very narrow and deep, 

 shorter than the aperture, umbilicus flaring, variable in diameter, deep, 

 bounded by the rounded edge of the fasciole, Avithin axially striated, but 

 not otherwise sculptured. Lon. of shell — ( ?) ; of last whorl from the 

 suture at the aperture forward 20.0; diam. of last whorl 21.5; of the um- 

 bilicus in two specimens 5.0 and 6.5 mm. respectively." Dall, 1890. 



The variation Avhich this species shows is amazing. In the material 

 from Jones Wharf there are forms which one could hardly hesitate to 

 refer to Ecphora quadricostata. These, by an increasing uniformity in 

 the prominence of the ribs, a narrowing of the umbilicus, and the gradual 

 appearance and increasing prominence of internal lirge on the labrum, 

 grade into forms like that from Church Hill which Dall figured as Rapami 

 tampaensis. Another gradation consists in the appearance of a small fold 

 on the columella. It was a specimen with this characteristic which Whit- 

 field referred to Fasciolaria {Lyrosoma) sulcosa. In other specimens the 

 ribs have become somewhat obsolete. 



Length, 38 mm. ; diameter, 25 mm. 



Occurrence. — Choptaxk Formation. Jones Wliarf, Dover Bridge, 

 Pawpaw Point, Trappe Landing. Calvert Formation. Church Hill, 

 Plum Point (?). 



Collections. — Maryland Geological Survey, U. S. iSTational Museimi. 



Family CORALLIOPHILID/E. 



Genus CORALLIOPHILA Adams. 



Coralliophila cumberlandiana (Gabb). 

 Plate LI, Figs. 18, 19, 20. 



Cautharus Cumberla7idiana Gabb, 1860, Jour. Acad. Nat. Sci. Pbila., 2nd ser., vol. 



iv, p. 375, pL Ixvii, fig. 6. 

 Cronia ? tridentata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. .568. 



(In part. Not Purpura tridentata T. and H.) 

 Coralliophila cumberlandiana Dall, 1890, Trans. Wagner Free Inst. Sci., vol. iii, 



pt. ii, p. 130. 

 Cantharus Cumherlandianus Whitfield, 1894, Mon. xxiv, U. S. Geol. Survey, p. 103, 



pi. xvii, figs. 3-6. 



Description. — "' Fusiform ; whorls five, prominent ; spire not as long as 

 the mouth; outer lip thick, with about eight teeth on its inner margin, 

 inner lip smooth and thin, a large plate of enamel on the columella and a 

 rudimentary tooth on the upper end near the suture ; umbilicus distinct 



