148 SYSTEMATIC PALEONTOLOGY 



constricted at the suture and obtusely angular and sometimes carinated 

 in the center; whorls with a minor carina at the suture and usually 8 or 

 10 revolving lines on each whorl of the spire ; body whorl strongly striate. 



Length, 33 mm. ; diameter, 10 mm. 



Occurrence. — Calvert Fokmation. Plum Point. 



Collections. — Maryland Geological Survey, Cornell University, U. S. 

 National Museum. 



Pleurotoma (Hemipleurotoma) choptankensis n. sp. 

 Plate XLI, Fig. 7. 



Description. — Shell subfusiform, nine-whorled ; whorls moderately 

 convex with sometimes a subsutural band which is flat or concave; lines 

 of growth strong, sometimes developing oblique costse on the shoulder; 

 notch moderately deep, situated at or slightly above the shoulder; sur- 

 face polished, and with faint impressed spiral lines, with slightly convex 

 interspaces, on the lower part of the body whorl; anterior canal of 

 moderate length, slightly curved. 



This species is very abundant at Jones Wharf. 



Length, 15 mm.; diameter, 4 mm. (maximum diameter, 7 mm.). 



Occurrence. — Choptank FoRMATioisr. Jones Wharf, Greensboro. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 



Pleurotoma (Hemipleurotoma) bellacrenata Conrad. 

 Plate XLI, Figs. 8, 9. 



riearotoma bellacrenata Conrad, 1841, Proc. Acad. Nat. Sci. Phila., vol. i, p. .30. 

 Flevrotoma bellacrenata Conrad, 1842, Jour. Acad. Nat. Sci. Pbila, vol. viii, 1st 



ser., p. 185. 

 Pleurotoma bellacrenata Conrad, 1842, Proc. Nat. Inst., BulL ii, p. 181. 

 Surcula bella-crenata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. .561. 

 Surcula bella-crenata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), 



p. 21. 

 Pleurotoma bellacrenata Harris, 1894, Amer. Jour. Sci., ser. iii, vol. xlv, p. 24. 



Description. — " Fusiform ; whorls much contracted below the middle, 

 with obsolete spiral lines, and crenate above the suture and on the 

 shoulder of body whirl; body whirl with five or six strong spiral stria?. 

 and an intermediate fine line; back finely striated. Length 1^ inch." 

 Conrad, 1841. 



