104 BEACHIOPODS. 



to four plications ; three or four elevations also occupy the 

 space on each side of the medial fold ; beak curved. Surface 

 of shell smooth. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City, Lexington. 



Meri stella laevis (VADNBXEM). 



Atrypa Icevis Vaunexem, 1843: Kept. Third Dist. N. Y., p. 120, fig. 2. 

 Merista Icevis Meek & Worthen, 1886: Geol. Sur. Illinois, vol. II, p. 376, 

 pi. vii, figs. 8a-c. 



In genera] appearance like Nucleospira pesiformis, but 

 much larger and longer. 



Horizon and localities. Upper Silurian limestone: Bailey 

 landing ( Perry county ). 



Eatonia peculiaris? (CONRAD). 



Atrypa peculiaris Conrad, 1841 : Ann. Bept, Pal. New York, p. 56. 

 Eatonia peculiaris Hall, 1859: Twelfth Ann. Kept. Keg. Univ. New York, 

 p. 37, figs. 1-7. 



Shell rather below medium size, slightly longer than wide. 

 Dorsal valve more convex than the ventral ; front elevated into 

 a prominent median fold. Ventral valve flattened, beak arched, 

 foramen terminal, small. Surface ornamented by small radiat- 

 ing ribs. 



Horizon and localities. Upper Silurian limestone : near 

 Grand Tower, in Perry county. 



Pentamerus ? salinensis SWALLOW. 



Penlamerus salinensis Swallow, 1860: Trans. ;Sc. Louis Acad. Sci., vol. 

 I, p. 652. 



Shell below medium size, ovoid. Ventral valve very con- 

 vex, abruptly arching to the sides, beak somewhat extended, 

 pointed, incurved ; foramen large, triangular. Surface marked 

 by about ten low plications, toward the anterior border. 



Horizon and localities. Devonian ? Callaway ? limestone : 

 Moniteau county (Swallow). 



