MARYLAND GEOLOGICAL SURVEY 153 



ridges; carinal ridge much stronger than the rest, next ridge closely 

 above it and much smaller, and between that and the suture the sur- 

 face is smooth save for faint, gentlj^ incurving lines of growth, which 

 are obsolete elsewhere. 



Length, 10 mm. ; diameter, 4.5 mm. 



This is referred to Surcula with considerable doubt, as the lip is 

 broken and the growth lines almost obsolete. 



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



Collection. — Marjdand Geological Survey. 



Genus MANGILIA Risso. 



Mangilia parva (CxDnrad). 



Plate XLII, Figs. 1, 2. 



Plenrotoma parva Conrad, 1830, Jour. Acad. Nat. Sci. Pbila., voL vi, 1st ser., p. 



225, pi. ix, fig. 18. 

 Surcula parva Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 561. 

 Surcula parva Meek, 1864, Miocene Checlc List, Smith. Misc. Coll. (183), p. 21. 

 Pleurotoma parva Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, pp. 34, 28. 

 Surcula parva ? Whitfield, 1894, Mon. xxiv, U. S. Geol. Survey, p. 117, pi. xxi 



fig. 1. 



Description. — " Shell subfusiform, transversely striated, with oblique 

 longitudinal ribs; upper part of the whorls concave and plain." Con- 

 rad, 1830. 



Shell, small, seven- to nine-whorled ; spire attenuate; beaks short, 

 slightly curved ; entire surface marked with fine, regular revolving lines ; 

 each whorl with about ten longitudinal ribs which terminate on the 

 shoulder in obtuse nodes; above the shoulder is a concave constriction 

 which extends to the suture and contains the siphonal notch. 



Length, 10 mm. ; diameter, 3 mm. 



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

 Langley's Bluff. Choptank Formation. Jones Wharf. Calvert 

 Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 TJ. S. National Museum, Philadelphia Academy of Natural Sciences, 

 Wagner Free Institute of Science, Cornell University. 



