Maryland Geological Survey 635 



on Polish Mountain, 1196 ?; 2 miles north of mouth of Town Creek 

 1312 ?, 1643 ?, 1842 ?; 2 miles west of Pawpaw, West Virginia 1493; 

 21/2 miles above mouih of Sideling Hill Creek ?; IS'ational Eoad west of 

 Tonoloway Eidge. 



Collection. — Marj'land Geological Survey. 



LiOPTERIA cf. BIGSBYI Hall 



Plate LXII, Fig. 12. 



Description. — A large individual, compared with L. hig'shyi, differs 

 from Hall's figure of that species in several respects. The umbo is more 

 attenuate, not appearing to be extended beyond hinge-line and wing is 

 not so sharply defined from umbo by a sulcus. 



Occurrence. — Jennings Formation, Chemung Member. National 

 Eoad, on Polish Mountain, 2714. 



Collection. — Maryland Geological Survey. 



LlOPTERIA MARYLANDICA n. Sp. 



Plate LXII, Figs. 13, 14 



Description. — Shell subrhomlioidal, body moderately oblique, broadly 

 ovate; length a little gTeater than width. Margins regularly rounded 

 ventrally, slightly extended posteriorly, valves moderately convex. Cast 

 slightly concave near anterior and posterior margin. Hinge-line straight, 

 umbo acute, arching over hinge. Ear short, rounded, limited by a sulcus. 

 Wing large, triangular, not sharply defined from body, its margin concave, 

 its extremity not observed. Cast of interior of left valve shows two 

 slightly oblique folds upon hinge, posterior to umbo. 



Length, 45 mm.; height 40 mm. 



The left valve only has been observed. This species closely resembles 

 L. greeni. It differs chiefly in its slightly concave margins and less 

 convex body. It may be a variety of that species. 



Occurrence. — Jennings Formation, Chemung Member. Town 

 Creek, 2023. 



Collection. — Manland Geological Survey. 



