224 SYSTEMATIC PALEONTOLOGY 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Wagner Free Institute of Science. 



Subgenus PYRGISCUS Philippi. 



TuRBONiLLA (Pyrgisccjs) interrupta (Totteu). 

 Plate lilV, Figs. 13, 14. 



Turritella interrupta Totten, 1835, Amer. Jour. Sci., vol. xxviii, p. 353, pL i, tig. 7. 

 Turbonilla interrupta Holmes, 1859, Post-Pleiocene Fossils of South Carolina, p. 83, 



pi. xiii, figs. 4, 4a, 4b. 

 Turbonilla interrupta Dall, 1893, Trans. Wagner Free Inst. Sci., vol. iii, pt. ii, p. 359. 



Description. — " Shell, sraalL subulate, brownish : volutions about ten, 

 almost flat, with about twenty-two transverse, obtuse ribs, separated by 

 grooves of equal diameter, and Avith about fourteen sub-equal, impressed, 

 revolving lines, which are arranged in pairs, and entirely interrupted by 

 the ribs : below the middle of the body whirl, the ribs become obsolete, 

 and the revolving lines continuous : sutures, made quite distinct by a 

 slight shoulder to each volution: apertures, ovate, angular above, regu- 

 larly rounded below, about one-fifth the length of the shell: right lip, 

 sharp, indistinctly sinuous." Totten, 1835. 



The form described by H. C. Lea as Pasithea siibula has some resem- 

 blance to this species but difliers from it in having the spiral lines finer, 

 and the body whorl less angular with the longitudinal ribs extending to 

 near the base and dying out gradually instead of ending abruptly on the 

 angle. 



Length, 11 mm. ; diameter, 2i mm. 



Occurrence. — St. Mary's Formation. St. Mary's River, Langley's 

 Bluff. Choptank Formation. Jones Wliarf, Greensboro. Calvert 

 Formation. Plum Point, Reeds, 3 miles west of Centerville. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Wagner Free Institute of Science. 



Subgenus TRAGULA .Monterosato. 



Turbonilla (Tragula) gubernatoria n. sp. 

 Plate LIV, Fig. 15. 

 Description. — Shell small, short, conical, thick, six-whorled; whorls 

 gently convex, with sixteen gently curved longitudinal ribs; lower half 



