210 Systematic Paleontology — Middle Devonian 



Genus VITULINA Hall 

 VlTULIKA PUSTDLOSA Hall 



Plate XX, Figs. 25, 26 



Vitulina pustulosa Hall, ISGO, Thirteenth Rep. N. Y. State Cab. Nat. Hist., 



p. 82. 

 Vitulina pustulosa Hall, 1867, Pal. N. Y., vol. iv, p. 410, pi. Ixii, figs, la-li. 

 Vitulina pustulosa Hall and Clarke, 1893, Pal. N. Y., voL viii, pt. ii, pp. 139, 



317, pi. Ixxxii, figs. 18-25. 

 Vitulina pustulosa Prosser, 1894, Bull. U. S. GeoL Surv., No. 120, p. 21. 

 Vitulina pustulosa Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 459. 

 Vihilina pustulosa Clarke, 1903, N. Y. State Mus., BulL 65, p. 345. 

 Vitulina pustulosa Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 351, fig. 458. 



Description. — Shell subplano-convex, semielliptical ; hinge-line equal- 

 ing or a little less than the width of the shell. Ventral valve convex; 

 median part raised in a broad fold which is subangnlar to flat near the 

 beak and grooved along the center to the front of the valve, with four or 

 five rounded or subangular plications on each side ; delthyrium large and 

 wide, reaching to the apex. Dorsal valve flat or slightly convex, with a 

 wide mesial depression which is nearly flat in the bottom, and in large 

 specimens contains a simple or double low plication toward the front; 

 plications on the side similar to those of the ventral valve; very narrow 

 cardinal area. Surface marked by interrupted radiating lines which 

 form rows of elongated pustules ; substance finely punctate. 



This is a rare species in Maryland but a few impressions have been 

 found on the National Road to the northeast of Cumberland. They are 

 mainly specimens of the ventral valve and one agrees quite closely with 

 the " ventral valve of a large individual " figured by Hall.' The propor- 

 tion of the width to the length of another specimen is somewhat greater 

 than in the New York specimens, while a fragment of an external im- 

 pression shows beautifully the impressions of the elongated pustules. The 

 author found abundant specimens of this species at Marshalls Falls, 

 Monroe Co. in northeastern Penna.; while there is a specimen of an 

 internal impression of a small ventral valve from Perry Co., Penna., in 



' Pal. N. Y., vol. iv, pi. Ixii, fig. la. 



