Prof. B. Silliman, Jr., on some American Minerals. 377 



ordinary bluish gray, soft argillo-silicious shale of the coal series, 

 and in spots are seen in immense numbers, from one to one and 

 a half feet above the coal. The shale is charged with myriads 

 of coal plants, but the only hint I have met with showing any 

 relation between this and other plants, is the fact, that where the 

 Pecopteris lonchitica is most abundant, this is seen in the great- 

 est numbers. The Tallmadge mines are in a bed, geologically, 

 at the base of the coal series, and from seventy-five to ninety feet 

 above the conglomerate. One of the sections of the leaf of the 

 Noeggerathia flabellata (Hutton and Lindley, plate 29), has an 

 edge marked somewhat like the specimen before us, but it is not 

 straight, the nerves are not as regular and distinct, and its base 

 is tapering and not an oval curve. Although there are thousands 

 of these impressions lying over and across each other, no con- 

 nexion exists between them as in the Noeggerathia. 



The Corpolithus is abundant in the roof of the same mine. I 

 believe the drawing taken with these remarks, will give a full 

 idea of this beautiful medal of ancient vegetation. In searching 

 for a description of it, or some analogue, I have had access to 

 only a part of the numbers of Brongniart. 



Cleavehind, Ohio, May 24, 1849. 



Art. XXIX. — Descriptions and Analyses of several American 

 Minerals ; by B. Silliman, Jr., M.D., Professor of Chemistry 

 applied to the Arts in Yale College, and of Medical Chemistry 

 and Toxicology in Louisville University, Ky. 



The results embodied in this article have been lately obtained 

 in the Analytical Laboratory of Yale College by myself, or by my 

 pupils under my immediate supervision and direction. 



The research upon the new and interesting species which be- 

 long to the family of micas is not complete : but as many months 

 *nust pass before I can again take up this investigation, it is 

 deemed best to present the results already obtained, that the at- 

 tention of mineralogists may be directed to them. I will present 

 in a second memoir, such further results as may be determined 

 by the analyses which will be carried forward this winter on the 

 same species. Enough has been done, it is believed, to give defi- 

 niteness and importance to the subject. 



The subjects treated of in this article are as follows : 

 . I- Description and analyses of several mineral species belong- 

 ing to the family Mica. 



II. Description and analysis of Unionife, a new mineral species. 



HI. Description and analysis of a species resembling Worthite. 



IV. Identity of Sillimanite, Bucholzite and Fibrolite with 

 Kyanite. 





