MARYLAND GEOLOGICAL SURVEY 149 



The siphonal notch is on the shoulder of the whorl and is very dis- 

 tinct. The lines of growth bend sharply at the base of the sinus. 



The beak is very short and somewhat twisted at the end, the twist ex- 

 tending upward on the columella. 



Length (restored), 45 mm.; diameter, 13 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Cornell University. 



Pleurotoma (Hemipleurotoma) calvertensis n. sp. 

 Plate XLI, Figs. 10, 11. 



Pleurotoma calvertensis ? Harris, 1893, Amer. Jour. Sci., ser. iii, voL xlv, p. 24. 

 (Name only.) 



Description. — Shell subfusiform, slender, eight-whorled ; upper third 

 of each whorl flat, with two or three impressed spiral lines; lower part 

 strongly convex, with rounded oblique costfe which are sometimes re- 

 curved at the upper end, and are usually crossed by about four fnint, 

 regular, impressed spiral lines and another stronger one above the suture ; 

 body whorl with about fifteen distinct impressed spirals below the cos- 

 tated shoulder; lines of growth strong, sweeping in broad curves around 

 the notch which is on the shoulder; surface polished; suture impressed; 

 beak short and slightly twisted. 



There is a specimen in the National Museum which differs from the 

 normal forms in having the longitudinal ribs almost obsolete, and in hav- 

 ing a deep impressed revolving groove a short distance below the suture. 



Length, 21 mm. ; diameter, 6 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Cornell University. 



Genus SURCULA H. and A. Adams. 



SuRCULA RUGATA Conrad. 



Plate XLI, Figs. 12a, 12b. 



Stircula rugata Conrad, 1862, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 285. 

 Surcula rugata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 561. 

 Surcula rugata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 21. 



Description. — "Fusiform, turriculate; whorls 10, lower half obtusely 



ribbed, upper half concave, subangular, with much curved, rugose lines 



