364 
PALEONTOLOGY OF NEW YORK. 
Seminula Rogersi, sp. nov, 
PLATE XLVII, FIGS. 1-4. 
Shell rather small, suboval in outline. Valves subequally convex. Pedicle- 
valve with a low, broad median sinus and brachial valve with a corresponding 
fold, both becoming more distinct toward the anterior margin. Lateral slopes 
depressed-convex. Umbonesnot conspicuous; deltidium concealed. 
External surface smooth. 
A normal individual measures 15 mm. in length, and 13 mm. in greatest 
width. 
Pendleton sandstone (Schoharie grit). Pendleton, Indiana. 
Athyris densa, sp. nov. 
PLATE XLVI, FIGS. 6-12. 
Shell transversely elongate, valves compressed; median fold and sinus not 
conspicuously developed. Pedicle-valve shallow, with broad, shiirply angled 
cardinal slopes, greatly thickened interiorly. The anterior margin is frequently 
extended into a linguate process at the termination of the median sinus. 
Brachial valve the more convex, with an indistinct, ilattened, and sometimes 
broadly grooved median fold with regular and even lateral slopes. In the 
interior of the valves the form of the muscular scars is normal, though there is 
a notable variation in the size of the diductor scars. 
St. Louis group. Washington county, Indiana ; Colesburgh, Kentucky. 
Seminula Dawsoni, sp. nov. 
PLATE XLVII, FIGS. 32-34. 
(See pages 95, 96.) 
This species was originally identified as Athyris suhtilita. Hall, by Davidson 
(Quarterly Journal of the Geological Society of London, vol. xix, 1863). Its 
differences from this species are indicated on the pages referred to. 
Carboniferous limestone. Windsor, Nova Scotia. 
