2GS Systematic Paleontology — Middle Devonian 



Cumberland ( ?) ; on Hancock-Harrisonville Eoad about 2 miles north of 

 Hancock; on National Eoad northeast of Cumberland; along Flintstone 

 Creek in Gilpin; on the Eomney-Hanging Eock Eoad about i mile north 

 of Eomney, W. Va. 



Collections. — Maryland Geological Survey ; New York State Museum ; 

 American Museum of Natural History. 



MoDiOMORPHA suBALATA (Conrad) 

 Plate XXXIII, Figs. 1-6 



Cypricardites subalata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 83. 

 Modiomorpha subalata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 77. 

 Modiomorpha subalata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata 



ii, p. 283, pi. XXXV, figs. C, 7; pi. xxxix, figs. 1-14, 16. 

 Modiomorpha subalata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 453. 

 Modiomorpha subalata Grabaii and Shimer, 1909, N. Am. Index Fossils, vol. 



i, p. 515, flg. 692b. 



D'escriptio7i ■ — "Shell of medium size or smaller, subquadrangular, or 

 subovate; subalate posteriorly, with the extremity obliquely truncate; 

 length more than one-third greater than the height; basal margin straight 

 or slightly concave on the anterior half, and thence regularly curving to 

 the post-basal extremity; posterior margin abruptly recurved below, and 

 continuing with a gentle curvature, or in a nearly straight line, to the 

 cardinal margin; cardinal margin oblique, nearly straight; anterior end 

 short, abruptly rounded, often a little concave below the beaks, and 

 limited by a more or less defined sinus, which extends from the beak to 

 the basal margin, usually at a point less than one-third the length of the 

 shell from the anterior end. Valves moderately convex below and in the 

 posterior portion, more convex in the middle; hinge-line oblique, about 

 half the length of the shell; bealcs subanterior, incurved and directed for- 

 ward, somewhat compressed; umbo prominent, flattened anteriorly; the 

 post-umbonal slope angular, gibbous above and gradually declining to the 

 post-basal extremity. Test thin, marked by fine concentric striae, which 

 are sometimes fasciculate, forming distinct elevations upon the posterior 

 slope, and often distinct angular striae upon the antero-basal portion of 



