1887.] NATURAL SCIENCES OF PHILADELPHIA. 47 



series of that section is not represented in any of the other 

 published sections in North America, tlie upper series may be 

 satisfactorily correlated with the western and upj)er Missouri 

 sections; and in part, at least, with the Cretaceous formations of 

 the Gulf, and Atlantic coast regions. 



In making these investigations the really valuable Avork of 

 Dr. B. F. Shumard has been adopted so far as practicable, and 

 a large proportion of the fossil species which he published, but 

 did not figure, have been recognized. The admirable work of 

 Prof. Roemer also is found to be as useful to-day as it was when 

 it was first published, forty years ago. 



ON ZINC MANGANESE, ASBESTOS. 



BY GE0RC4E A KOENIG, PH. D. 



During a visit to the Franklin Zinc Mines in 1879, I obtained 

 from Mr. George, then Superintendent of the Trotter mine a 

 considerable quantity of Sussexite. Among this there was some 

 material which did not quite look like the rest, and was subjected 

 to an investigation. This material I will designate A. After 

 finding it of interest, I obtained from my friend and colleague, 

 Dr. F. A. Genth, a bluish asbestiform mineral from the same 

 locality ; this will be designated as material B. 



Both appear as stiff", rather columnar fibres, and effervesce with 

 acid. But after treatment with dilute HCL, a fine silky mass ot 

 fibres remain, and these were analyzed. The needles appeared 

 under the microscope slightly yellowish or colorless, whilst the 

 substance in bulk appeared bluish, like crocidolite or brown black. 



These needles fuse readily before the blow-pipe with intumes- 

 cence to a black globule, and behave thus like Sussexite. But 

 no color is given to the flame, so characteristically green in 

 Sussexite. 



