188 SYSTEMATIC PALEONTOLOGY 



column with one large, very sharp tooth at right angles to the axis of the 

 shell; space between the columella and posterior end of the outer lip 

 polished, not callous. Lon. of shell, 4.12; of last whorl, 2.50; of 

 aperture, 1.75; max. lat. of shell, 2.00 mm." Dall, 1883. 



Only a single specimen of this species has been found in Maryland. It 

 has been recognized in the Miocene of New Jersey and North Carolina, 

 and in the Pliocene and Pleistocene of Florida. It is found living from 

 Cape Hatteras to Florida and on the Gulf coasts. 



Occurrence. — Talbot Formation. Wailes Bluff near Cornfield Har- 

 bor, St. Mary's County. 



Collections. — U. S. National Museum. 



Genus TURBONILLA Risso. 

 Subgenus PYRGISCUS Philippi. 



Turbonilla (Pyrgiscus) interrupta (Totten) 



Plate L, Figs. 9, 10. 



Turritella interrupta Totten, 1835, Amer. Jour. Sci., vol. xxviii, p. 352, fig. 7. 

 Turbonilla interrupta Holmes, 1859, Post-Pi. Fos. S. C, pp. 83, 84, pi. xiii,. 



figs. 4, 4a, 4b. 

 Turbonilla quinquestriata Holmes, 1859, op. cit. p. 85, pi. xiii, figs. 5, 5a, 5b. 

 Turbonilla lineata Holmes,' 1859, op. cit. p. 85, pi. xiii, figs. 7, 7a, 7b. 

 Turbonilla subulata Holmes, 1859, op. cit. p. 85, pi. xiii, figs. 8, 8a, 8b. 

 Turbonilla acicula Holmes, 1859, op. cit. p. 85, pi. xiii, figs. 10, 10a, 10b. 

 Turbonilla interrupta Dall, 1892, Trans. Wagner Free Inst. Sci., vol. iii > 



pt. 2, p. 259. 

 Turbonilla (Pyrgiscus) interrupta Martin, 1904, Md. Geol. Survey, Miocene, 



p. 224, pi. liv, figs. 13, 14. 



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

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

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

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

 tbe 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. 



