MARYLAND GEOLOGICAL SUKVEY 159 



Description. — " Shell subfusiform, glabrous, with short oblique lon- 

 gitudinal ribs; whorls concave above and plain; left lip reflected over 

 the columella with a callus at its superior termination." Conrad, 1830. 



The specimens from Jones "Wharf have impressed revolving lines on 

 the base of the body whorl. Those from Plum Point are intermediate 

 between limatula and lunata of H. C. Lea. They might be considered 

 as a variety of either species. 



Length, 40 mm.; diameter, 11 mm. (Plum Point). Length, 22 mm.; 

 diameter 7 mm. (St. Mary's Eiver). 



Occurrence. — St. Mary's Formation. St. Mary's Eiver, Cove Point, 

 Langley's Bluff. Choptank Formation. Jones Wharf, Flag Pond. 

 Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survej^, Johns Hopkins University, 

 U. S. National Museum, Philadelphia Academy of Natural Sciences, 

 Cornell University. 



Drillia limatula var. DissiMiLis Conrad. 

 Plate XLII, Figs. 14, 15. 



Pleurotoma dissimilis Conrad, 1830, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st sen, 



p. 224, pi. ix, fig. 11. 

 Drillia dissimilis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 562. 

 Drillia dissimilis Meek, Miocene Check List, Smith. Misc. Coll. (183), p. 21. 



Description. — " Shell conical, smooth ; spire with obsolete oblique 

 nodules joining the suture at the base of each volution; suture im- 

 pressed; left lij) with a callus at its superior termination; columella 

 truncated; a slight sinus at the base of the right lip." Conrad, 1830. 



This difi;ers from limatula only in that the nodular ribs are more 

 nearly obsolete. 



Length, 21 mm.; diameter, 7 mm. 



Occurrence. — St. Mary's Formation. St. Mary's River, Cove Point, 

 Langley's Bluff. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Philadelphia Academy of Natural Sciences, 

 Cornell University. 



