Winehell.] ^4o [Jan. 4, 



Li:ngtjla subspatulata? M. & W. (111. Geol. Rep. Ill, 437, pi. 13, fig. 

 1). From Tennessee, and No. 6, Rockville, Ohio. The single specimen 

 from Tennessee, showing the inside of (apparently) the ventral valve, is 

 not over one-third the length of the specimen figured in the Illinois Re- 

 port ; hut it otherwise agrees with the description in outline, surface 

 markings, position of beak and faint radiating lines along the middle. 



Lingula subspatulata was described from the "Black Slate," of Union 

 county, 111. At Vanceburg, Ky., and other localities on both sides of the 

 Ohio river, is a black shale embraced within the Waverly series, (see No. 

 6, Andrews' section) which contains a small Lingula, not easily distin- 

 guishable from the Tennessee specimen. If the Ohio, Kentucky, and 

 Tennessee specimens are really identifiable with the Illinois species, it ap- 

 pears strange that the latter should be found in a geological position so 

 much lower. There seems to be occasion for the query, whether the Illi- 

 nois equivalent of the Vanceburg Shale has not become confounded with 

 the ' ' Black Shale, ' ' by the disaj^pearance of intervening beds ; and also, 

 whether the entire mass of the "Black Shale," of southern Ohio, Indi- 

 ana and Illinois, does not, in fact, belong in a position considerably above 

 the Genesee Shale, as Verneuil, Owen and others long ago suggested. ^^i 



I am led to suspect that L. subspatulata, M. & W., is identical with my 

 L. membranacea.''^^'^ 



Lingula membranacea, Win. (Proc. x\cad. N. S., Phil., Jan., 1863). 

 From near Shafer's, Penn. 



DlsciNA Saffordi, n. sp. 



Shell rather small, outline nearly circular, but generally a little flattened 

 posteriorly, and also on each of the postero-lateral boundaries. Upper 

 valve rather depressed conical, with the beak midway between the centre 

 and the posterior side ; under surface presenting a faint but distinct 

 linear ridge extending anteriorly from the beak one-fourth the diameter of 

 the shell. Lower valve very depressed convex, with an apical pyriform 

 indentation having a blunt spur projecting from its broad anterior end ; 

 no perforation visible. Exterior of both valves ornamented with numer- 

 ous fine, unequal, concentric striae ; interiors smooth, except the faint 

 vascular markings near the borders. 



This curious species most resembles in general appearance, Discina Lo- 

 densis, from the Genesee Shale ; but the pyriform indentation of the ven- 

 tral valve, the finer external striae and the inconspicuous foramen will 

 serve to distinguish it. 



From dark bituminous Shales just above the "Black Slate," of Hick- 

 man county, Tennessee, 



121 The "Black Shale," of northern Ohio, Ontario and Michigan, is undoubtedly the "Genesee," 

 as is proven both stratigraphically and paleontologically. (See Proc Amer. Phil. Soc, No. 81, p. 

 77, &c.) 



122 1 take occasion to remark that Gyroceras? Rocl-fordensis, M. & W., (111. Rep. Ill, p. 459) from 

 Rockford, Ind., is Identical with my Cyrtoceraa Roch-fordtnse, described in Proc. Acad. Nat. Sci. 

 July, 186j. 



