162 SYSTEMATIC PALEONTOLOGY 



forms), but are separated by their greater strength of ribbing and lack 

 of flat tops on the whorls. The intermediate line is not a constant 

 character. 



Length, 16 mm.; diameter, 10 mm. 



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

 Choptank Formation. Jones Wharf, Greensboro, Sand Hill (?), 

 " Choptank River" (Conrad). Calvert Formation. Plum Point, 

 Church Hill, 3 miles west of Centerville. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

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



Cancellaria engonata Conrad. 

 Plate XLIII, Fig. 4. 



Cancellaria engonata Conrad, 1841, Proc. Acad. Nat. Sci. Phila., vol. i, p. 32. 

 Cancellaria engonata Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, 1st ser., 



p. 188. 

 Cancellaria engonata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 567. 

 Cancellaria engonata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 17. 

 Cancellaria engonata Conrad, 1866, Amer. Jour. Conch., vol. ii, p. 68, pi. iv, fig. 8. 

 Cancellaria engonata Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, p. 24. 



Description. — " Short fusiform, with strong spiral prominent lines; 

 and numerous longitudinal costae, not so distinct as the transverse lines; 

 spire scalariform, volutions 4; columella with three plaits, the middle 

 one very oblique; submargin of labium with prominent transverse lines. 

 Length, f inch.-" Conrad, 1841. 



" Short-fusiform, longitudinally ribbed, with prominent revolving 

 lines, about 12 in number, from the sho.ulder to the base; whorls 5; 

 spire conical, scalariform; aperture lunate; columella three-plaited, the 

 middle one very oblique." Conrad, 1866. 



Conrad's specimens were immature and his figure and descriptions 

 are not characteristic. The species may be re-defined as follows: 



Shell subfusiform, six-whorled; whorls very convex, deeply constricted 

 at the suture, and widest about one-third the distance from the top; 

 top of the whorl flat, slightly domed, or concave; whorls of the spire 

 with twelve strong, raised, revolving ribs with wider interspaces; body 

 whorl with twelve ribs below the shoulder, and nearly as many smaller 



