G34 Systematic Paleontology — Upper Devoniax 



show an oblique lateral tooth, with <)l)scui-o iudications of anterior teeth 

 or folds. Ligamental area narrow, marked with fine parallel striae. A 

 left valve has a length of 45 mm. ; height 50 mm. ; hinge-line, wlien en- 

 tire, about 75 mm. A small right valve has a length of 34 mm., height 

 27 mm., hinge-line about 45 mm. This species is distinguished by the 

 great and nearly equal extent of the hinge-line on both sides of the 

 beak; by the peculiar form of the body of tlie shell; and by its surface 

 characters, which are unlike any yet observed." Hall, 1884. 



This species is characterized by its greatly elongated, acute, cardinal 

 angles. It is an abundant and characteristic species of the Ithaca faunr, 

 of Maryland. 



Occurrence. — Jennings Formatiok, Woodmont Member, Ithaca 

 Fauna. Two miles west of Pawpaw, West Virginia, 1340, 1388; Little 

 Orleans, 1446; Fifteenraile Creek, 1 mile above Little Orleans, 144G; 

 Woodmont 1032; Yellow Springs, West Virginia. 



Collection. — Maryland Geological Survey. 



Genus LIOPTERIA Hall 

 Liopteria bigsbyi Hall 

 Plate LXII, Figs. 10, 11 



Liopteria bigsbyi Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 165, pi. xx, figs. 3, 

 11, 13-15; pi. Ixxxviii, fig. 23. 



Description. — Shell moderately large, suberect, broadly ovate body. 

 Height greater than length. Anterior margin nearly vertical for about 

 half the height of the shell, thence regularly rounded along the base. 

 Both valves convex on the umbo, the right valve becoming depressed 

 over the body. Hinge-line straight and less than the length of tlie shell. 

 Beaks anterior, ear short, wing triangular and flat. Surface witli lamel- 

 lose concentric striae. 



Length 30 mm.; height 30 mm. 



Occurrence. — Jennings Formation, Chemung Member. Towti 

 Creek, 2023. Parkhead ^Member. Two and one-quarter miles south- 

 east of Cumberland ?; Williams Eoad, 3% miles east of Cumberland, 

 1466 ; Williams Road, on Polish Mountain, 1289 ?, 1660 ; National Eoad, 



