MARYLAND GEOLOGICAL SURVEY 233 



Description. — " Shell terete, slender, adhering in large groups, occa- 

 sionally angulated, with sessile spiral convolutions; surface with acute 

 prominent transverse wrinkles." Conrad, 1839. 



" Terete, slender, adhering, with strong annular wrinkles; toward the 

 apex are contiguous volutions, somewhat angular or suhcarinated ; the 

 whorls with obsolete revolving lines and suhcarinated near the base ; inter- 

 nally furnished with vaulted septa." Conrad, 1845. 



This species differs from V. graniferus in being less intricately coiled 

 and in being destitute of all sculpture except annular wrinkles and lines 

 of growth. 



Diameter of tubes, 3 mm. 



Occurrence. — St. Mary's Formation. Cove Point. Choptank For- 

 mation. Jones Wharf, Greensboro, Cordova. Calvert Formation. 

 Plum Point, Chesapeake Beach. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum. 



Family TURRITELLID/E. 



Genus TURRITELLA Lamarck. 



Turritella indenta Conrad. 



Plate LVI, Figs. 1, 2. 



Turritella indenta Conrad, 1841, Proc. Acad. Nat. Sci. Phila., voL i, p. 33. 

 Turritella indenta Conrad, 1843, Jour. Acad. Nat. Sci. Pbila., voL viii, 1st sen, 



p. 188. 

 Turritella indenta Conrad, 1843, Proc. Nat. Inst., Bull, ii, pp. 183, 183. 

 Turritella tndenta Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 568. 

 Turritella indenta Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 16. 

 Turritella indenta Conrad, 1868, Amer. Jour. Conch., vol. iii, p. 358, pi. xxi, fig. 3. 

 Turritella indenta Dall, 1893, Trans. Wagner Free Inst. Sci., vol. iii, pt. ii, p. 308. 

 Turritella indenta Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, pp. 24, 35. 



Description. — " Subulate, whirls about 15, contracted or indented above 

 the middle, and with obsolete spiral stri^; suture profound, the lower 

 margin obtusely carinated by the indentation; the upper margin also 

 suhcarinated; basal margin acutely angulated; base flat or slightly con- 

 cave." Conrad, 1842. 



" Broad at base ; whorls each with two revolving obtuse lines, the in- 

 ferior one largest, subtuberculated and margins the suture, and an im- 



