MaHYLAND GliOLOdlCAL SUUVEY 339 



SCHUCHERTELLA BECRAFTENSIS (Clarke) 



Plate LX, Figs. 10-13 



Orthothetes becraftensis Clarke, 1900, Mem. N. Y. State Mus., vol. iii, No. o, 

 p. 51, pi. vii, figs. 15-28. 



Description. — " Shell small, suborbicular or elongate in outline. 

 Pedicle valve erect at the beak, nmbonal region generally sloping directly 

 or with low convexity to the peripheral margins ; sometimes slightly de- 

 pressed about the umbo. Brachial valve depressed at and about the beak, 

 becoming convex over the median and anterior regions. Surface of both 

 valves covered with strong, rounded strite increasing by implantation, 

 new striae generally appearing in successive cycles. The surface also bears 

 exceedingly fine, concentric lines which are visible in the interspaces but 

 seldom cross the radial striae. Concentric varices of growth are also fre- 

 quent, especially near the margins. 



" The cardinal area of the pedicle valve is triangular, broad and erect, 

 seldom showing distortion. In but a single instance has attachment been 

 observed The deltidium is pronounced. On the interior the mark- 

 ings are those characteristic of the genus; the brachial valve bears an 

 erect, continuous cardinal process, divided into two lobes, each grooved on 

 its outer face. The lateral walls of this process are continued inward to 

 form the strong dental sockets." Clarke, 1900. 



Length 8 mm. to IT mm. ; width 13 mm. to 31 mm. 



As Clarke states, this small Oriskany species has no close ally in the 

 Devonian faunas and its nearest approach is found in the 0. arctostriata 

 of the Hamilton. 



Occurrence. — Oriskany Formation, Shriver Member. North 

 Branch. Eidgely Member. Williams Eoad near Cumberland. 



Collection. — Maryland Geological Survey. 



Schuchertella deokerensis (Weller) 

 Plate LX, Figs. IS-IG 



Orthothetes deekerensis Weller, 1903, Geol. Survey N. J., Pal., vol. ili, pp. 

 229-230, pi. XX, figs. 6-7. 



Description. — " Shell subplano-convex, transversely sabelliptical in out- 

 line, the hinge-line shorter than the greatest width of the shell, which is 



