Maryland Geological Survey 551 



Occurrence.— Jennings Formation, Chemung ? Member. West 

 slope of Polish Mountain on National Road. 

 Collection. — IMaryland Geological Survey. 



Order PROTREMATA 



Superfamily STROPHOMENACEA 

 Family STROPHOMENIDAE 



Genus STROPHEODONTA Hall 



Stropheodonta demissa (Conrad) ' 



Plate XLVII, Fig. 14 



Description. — Well-characterized specimens of this species occur not 

 rarely in the Ithaca fauna. A single individual is recorded from the 

 Chemung. 



Length 25 mm. ; width 30 mm. 



Occurrence. — Jennings Formation, Chemung Member. Oakland- 

 Altamont Iload. AVoodmont Member, Ithaca Fauna. Two miles west 

 of Pawpaw, West Virginia, 1388; Little Orleans, 1446; Fifteemnile 

 Creek, 1 mile above Little Orleans, 1446 ; Hancock, 672 ; Hancock-Harris- 

 sonville Road, 882; Berkeley Springs, West Virginia, 712, common; 

 Yellow Springs, West Virginia. 



Collection. — Maryland Geological Survey. 



Stropheodonta maynardi n. sp. 



Plate XLVII, Figs. 15-18 



Description. — Shell large semielliptical, planoconvex, cardinal extremi- 

 ties long mucronate, hinge-line much longer than width of shell. Ventral 

 valve convex, point of greatest convexity near umbo; surface curving 

 regularly toward front, concave toward cardinal angles. Dorsal valve 

 nearly plane, bearing low radiating fold-like plications. Area narrow, 

 hinge-line crenulated. Surface bears numerous strise, the direction of 



' For synonymy and description see page 136. 



