The E'ew Species of Brachiopoda, 359 



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, flattened, and some- 

 times 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; Coleshurgh, 

 Kentucky. 



Seminula Rogersi. 

 Plate 9, figs. 10-13. 



Seminula Rogersi, Hall. Palaeontology of N. Y., vol. VIII, pt. 2, p. 364, pi. 

 xlvii, figs. 1-4. 1894. 



Shell rather small, suboval in outline. Yalve subequally con- 

 vex. 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. 

 Umbones not conspicuous ; deltidium concealed. 



External surface smooth. 



A normal individual measures 15 mm. in length, and 13 mm. in 

 greatest with. 



Pendleton sandstone (Schoharie grit). Pendleton, Indiana. 



Seminula Dav7Soni. 



Plate 9, figs. 14-16. 



Seminula Dawsoni, Hall. Palaeontology of N. Y., vol. VIII, pt. 2, p. 364, pi. 

 xlvii, figs. 32-34. 1894. 



This species was originally identified as Athyris subtilita, 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. 



Torynifer criticus. , 



Plate 9, fig. 1. 



Torynifer criticiis, Hall. Palaeontology of N. Y., vol. VIII, pt. 2, expl. pi. 

 Ixxxiv, figs. 34, 35. 1894. 



Shell but imperfectly known. The pedicle- valve has a smooth 

 exterior, narrow cardinal area and unclosed dilthyrium. On the 



