MARYLAND GEOLOGICAL SURVEY 255 



Occurrence. — St. Mary's Formation. St. Mary's Eiver, Cove I*oint, 

 Langley's Bluff. Choptank Forheation. Jones Wharf, Governor Run, 

 2 miles south of Governor Run, Pawpaw Point, Flag Pond, Dover Bridge, 

 Sand Hill. Calvert Formation. Plum Point, 3 miles west of Center- 

 ville, Fairhaven. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Philadelphia Academy of Natural Sciences, Cor- 

 nell University. 



Genus Sigaretus Lamarck. 



Sigaretus fragilis Conrad. 



Plate LX, Figs. 5a, 5b. 



Natica fragilia Conrad, 1830, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st ser., p. 232, 



pL ix, fi}r. 3. 

 Sigaretus frayihs Conrad, 1843, Proc. Nat. Inst., BuU. ii, p. 181. 

 Natica aperta H. C. Lea, 1843, New Fossil Shells from the Tertiary of Virginia, 



Abst., p. 7. 

 Natica aperta H. C. Lea, 1845, Trans. Amer. Philos. Soc., vol. ix, p. 254, pi. xxxvi, 



fig. 51. 

 Natica fragilis Emmons, 1858, Rept. N. Car. Geol. Survey, p. 367, fig. 153. 

 Sigaretus [Naticina) fragilis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, 



p. 565. 

 Sigaretus fragilis Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 19. 

 Sigaretus fragilis Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, p. 35. 



Description.—" Shell ovate, thin, fragile, smooth, with fine revolving 

 impressed striae ; spire very small ; apex acute ; aperture extending about 

 four-fifths of the length of the shell; columella much narrowed and arcu- 

 ated, exhibiting the internal volutions." Conrad, 1830. 



Height, 22 mm. ; width, 18 mm. 



Occurrence.— St. Mary's Formation. St. Mary's River, Cove Point. 

 Choptank Formation. Governor Run (lower bed). Calvert Forma- 

 tion. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum. 



