1S70.] 251 [WinehcU. 



imlchella, Win. The type-specimens of C. geniculata are from Clarksvillo, 

 Mo., and, besides presenting the characteristic geniculation in the ventral 

 valve, appear to have a rather shorter hinge line than these specimens. 



Chonetes Illinoisensis, Worthen (^Trans. St. Louis Acad. Sci. I, 571). 

 Occurs in bed No. 5, Rockville, Ohio. 



Hemipronites iNEQXJALis, Hall sp. (To. Geol. Eep. 490, pi. ii, fig. G, 

 a — c.) Collected by Rev. H. Herzer, at Newark, Ohio, and by Prof. An- 

 dre^ys, at Granville. Collected, also, by the latter in Pennsylvania, near 

 Shafer's. 



Hemiprokites TJMBEACULTJM ? Schloth. (Die Petrcfact. I, p. 256, and 

 II, p. 67.) 



Collected by Rev. H. Herzer, at Newark, Ohio, and by Prof. Andrews, 

 in bed No. 4, at Sciotoville and bed No. 5, Rockville, and also, near 

 Shafer's, Penn. 



It may well be doubted whether the large specimens ranging through 

 the equivalents of the Marshall group, in the Western States, really be- 

 long to the foreign species to which they have generally been referred. 



Okthis subelliptica ? W. & W. (Bos. Proc. YIII, 292.) From bed 

 . No. 4, Sciotoville, Ohio. A single imperfect specimen. 



OrTHIS MiCHELIKI '? L'EveiUe. 



From bed No. 5, Rockville, Ohio ; from Granville, Licking county; 

 from Vinton county; and also, from near Shafer's, Penn. 



The specimens from all these localities agree with each other and Avith 

 specimens commonly referred to 0. Michelini. It is a form probably iden- 

 tical with that from Clarksville, Mo., referred to 0. Vamtxemi, by Prof. 

 Hall. The smaller, flattened specimens approximate 0. flava, Win., from 

 the Burlington Sandstone, while a large, transversely oval specimen, 

 from Rockville, approaches 0. resiipinaia, except in much smaller size. 

 In the considerable convexity of some of the dorsal valves (especially from 

 Shafer's J, and also in the cast of the muscular scars, they differ from 0. 

 impresm, Hall. If there are any permanent specific distinctions among 

 the widely extended American forms commonly referred to 0. Michelini, 

 it will require extended and careful comparisons to make them out. 



Spiripeea niRTA? White & Whitfield. 



The single specimen from silicious Shales, Tennessee, is considerably 

 larger than specimens from Burlington, Iowa, the typical locality, and 

 perhaps the area is a little more extended laterally. 



Spirifeea EXTENUATA, Hall flowa Rep. 520, pi. vii, fig. 6). Collected 

 by Rev. H. Herzer and Prof. Andrews, at Newark, 0. 



Spieifera Waverlyensis, n. sp. 



Shell semi-circular, without plications (on the cast). Yentral valve 

 with an elevated, nearly flat, transversely furrowed and vertically striated 

 area, reaching the whole length of the hinge-line, which is scarcely less 

 than the greatest width of the valve. The plane of the area forms a right 

 angle with the plane of the valve. Surface more rapidly convex near the 

 nmrgin than between the beak and the middle ; lateral slopes, also, gent- 

 ly convex. Sinus deep, well defined, occupying nearly one-fourth the 



