182 PROCEEDINGS OF THE ACADEMY OP [1892. 



On the right bank of tlie river, besides the breunnerite, asbestus was 

 at one time found in considerable quantity. 



About a half mile above the soapstoue quarry and a quarter of a 

 mile westward from the river was Rose's quarry, in a hard black 

 serpentine of the Lafayette belt. Here were found asbestus, ensta- 

 tite, Schiller spar and antigorite. 



On the Wissahickon, the line of demarkation between the INfana- 

 vuuk schists and the Chestnut Hill schists is obscure. Below Gor- 

 gas' Lane menaccanite in quartz occurred. Above Gorgas' Lane 

 was found halotrichite. Near Cresheim Creek antholite in radiated 

 masses is abundant, also staurolite and kyanite in the mica schists, 

 in poor specimens, and garnets in great quantity but poor. Very 

 recently fine kyanite was obtained. AVhere the steatite belt crosses, 

 near Thorp's Lane, magnetite in octahedra, talc and steatite are 

 found. Hyalite is found occasionally coating the schists. 



On the Schuylkill, the tunnel of the Reading Railroad through 

 the Manayunk schists at Flat Rock afforded fine specimens of red 

 stilbite, also lieulandite, beryl and calcite. On the left bank, nearly 

 opposite the tunnel, were found brown spar and ilvaite. At Hea- 

 cock's quarry in the Chestnut Hill schists at Jenkintown, North 

 Pennsylvania Railroad, Mr. Edward D. Drown found an albite 

 granite containing very minute green crystals which a microscopic 

 examination proves to be torbernite. This is an interesting dis- 

 covery. 



Northwest of the Chestnut Hill schists is a hill, often of great 

 l^eight, and almost continuous from Trenton, N. J., to beyond the 

 Brandywine. This is of Laurentian gneiss. It is, except in one 

 place, singularly barren of crystallized or rare minerals. This ex- 

 ception is the well-known Vanartsdalen's quarry near Feasterville, in 

 Bucks County, where a small bed of limestone is exposed and here 

 we find many of the minerals found in the Laurentian limestones of 

 Canada. This is the only observed out-crop of limestone in the 

 whole length of the Laurentian in this part of the State. The rock 

 is mostly granular and crystalline and much mixed with other 

 minerals, particularly phlogopite, pyroxene and graphite. The fol- 

 lowing minerals have been found: — 



Blue quartz, which, while abundant in massive specimens through- 

 out the whole Laurentian range, was in specimens of unusually 

 good color at this quarry; orthoclase, massive, of a gray color, 

 translucent, almost transparent, with the cleavage surfaces very 



