MARYI.AND GEOLOGICAL SUEVE-S 199 



Tritia (Bulliopsis) marylandica Meek, 1S64, Miocene Check List, Smith. Misc ColL 



(183), p. 20. 

 Nasm [Bulliopsis) Marylandica Conrad, 1866, Amer. Jour. Conch., vol. ii, p. 05 



pL iii, fig. 3. 

 Melanopsis Marylandica Conrad, 1S6S, Amer. Jour. Conch., voL iii, p. 259. 



Description. — " Oblong-ovate, entire; whorls 6, slightly convex or sub- 

 truncated laterally ; suture impressed ; aperture about half the length of 

 the shell; columella profoundly callous above, the callus extending 

 beyond the lip." Conrad, 18G3. 



The surface is frequently marked with obsolete revolving lines. 



Length, 32 mm. ; diameter, 14 mm. 



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



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Philadelphia Academy of Is^atural Sciences. 



Family COLUMBELLID/E. 



Genus COLUMBELLA Lamarck. 



Subgenus ASTYRIS Adams. 



COLUMBELLA (ASTYRIS) COMMUNIS (C/DUrad). 



Plate L, Figs. 5, 6, 7. 



I^assa Innata Conrad, 1830, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st ser., p. 311. 



(Not of Say.) 

 Buccinum lunatum Conrad, 1842, Proc. Nat. Inst., Bull, ii, p. 187. 

 Amycla [Astyris) communis Conra.^, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 287. 

 Amycla (Astyris) communis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 564, 

 Coliimbella (Astyris) communis Dall, 1890, Trans. Wagner Free Inst. Sci., vol. iii. 



pt. i, p. 138. 

 Astyris communis Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xiv, p. 38. 

 Amycla communis Whitfield, 1894, Mon. xxiv, U. S. Geol. Survej', p. 110, pi. xix, 



figs. 13-15. 



Description. — " Small, whorls six or seven, smooth and polished ; spire 

 rather elevated; body whorl abruptly rounded in the middle, or subangu- 

 lar; submargin of labrum minutely dentate." Conrad, 1862. 



AMiorls slightly convex, covered with minute spiral lines visible only 

 through a lens ; beak with from 8 to 12 distinct impressed revolving lines ; 

 labrum sometimes straight, sometimes rounded; usually smooth within, 

 often strongly dentate; labium usually somewhat callous, sometimes den- 

 tate. The callous dentate labrum occurs only in specimens from the St. 

 Mary's Formation and most typically in those from Cove Point. 



