MARYLAND GEOLOGICAL SURVEY 141 



except the specimen with sharp revolving lines which Whitfield had pre- 

 viously figured as " figs. 15-17."' This variety is probably the prede- 

 cessor of T. simplex, to which it has a strong resemblance. 



Length, 27 mm.; diameter, 9.5 mm. 



Occurrence. — Choptank Formation. Greensboro, Jones Wharf, 

 Sand Hill (?). Calveut Formation. Plum Point, Church Hill, 3 

 miles south of Chesapeake Beach. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. N^ational Museum, Cornell University. 



Terebra (Acus) curvilineata var. calvertensis n. var. 

 Plate XL, Figs. 6, 7. 



Description. — Shell elongate, tapering slowly; whorls constricted about 

 one-third of the way below the suture by a distinct groove above which 

 the ribs are strongly tuberculate; ribs straight, regular, distant; no 

 spiral sculpture. 



Length (of fragment), 17 mm.; diameter, 5 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum. 



Terebra (Acus) gurvilirata Conrad. 

 Plate XL, Fig. 8. 



Terehra curvilirata Conrad, 1S43, Proc. Acad. Nat. Sci. Phila., vol. i, p. 3:27. 

 Tei-ehra curvilirata Conrsid, 1868, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 56.5. 

 Terebra (Acus) curinlineata .Meek, 1864, Miocene Check List, Smitti. Misc. Coll (183) 

 p. 18. 



Terebra curvilineata VVhittiekl, 1894, Hon. xxiv, U. S. Geol. Survey, p. 113. (In 

 part.) 



Terebra (Acus) ourinlirata Dall, 189.5, Proc. U. S. Nat. Museum, vol. xviii |No. 103.51 

 p. 37. " 



Not Terebra curvilirata Heilprin. 



Description. — " Subulate, whorls with a revolving impressed line be- 

 low and near the suture; beneath this line the whorls are convex; ribs 

 longitudinal, curved, acute, dislocated by the impressed line; revolving 

 lines minute, crowded, obsolete; columella sinuous. Length one and a 

 quarter inches. 



"Differs from Cerithium dislocatum, Say, in wanting the distinct re- 



