OF ARTS AND SCIENCES : MAY 25, 1869. 115 



connected with the outbreak of the granite. Probably the lapse of 

 time between the deposition of 3 and 5 was of long duration, and it is 

 quite likely that the gap may comprise a series of sedimentary deposits 

 which are not visible at the surface in the regions visited by me. I did 

 not even see in any place the lowest portion of the Tung-ting sand- 

 stones. They form a rather uniform series of very hard, almost 

 quartzose sandstones, which are visible in a thickness of at least four 

 thousand feet, and form bold mountain ranges for themselves alone, the 

 Liu-shan among others. The name was first used by Kingsrnill, and 

 is derived from the island of Tung-ting-shan in Taihu Lake, sixty 

 miles west of Shanghai. 



This is the only formation in regard to the position of which I do 

 not feel quite certain. The next formation is, however, conformably 

 underlain by what I consider to be the topmost layers of the Tung-ting 

 sandstone, namely, a series of hardened, nodular clay, hard sandstone, 

 and conglomerate of pebbles of quartz. 



6th. Si-hio limestone. — This is a limestone formation of only six hun- 

 dred feet in thickness. The rock is full of chert nodules, and contains 

 numerous fossils, chiefly corals, encrinites, and brachiopods. Aulopora 

 repens is of frequent occurrence among them, and other forms, too, 

 indicate a Devonian age. The name is derived from a prominent hill, 

 generally known as Single-tree hill, east of Nan-king, where I first 

 found the fossils. 



7th. Nan-king grits. — The last formation is conformably overlain 

 by a gritty and purely quartzose sandstone, alternating frequently 

 with a coarse conglomerate of perfectly rounded pebbles consisting 

 exclusively of quartz. The color is mostly red, but where the strata 

 are inclined at steep angles, light shades prevail, though the former 

 color is still visible in concentric rings of a dark red color, which give 

 a variegated appearance to every plane of fracture. Although this 

 formation is largely developed at and around Nan-king, and forms 

 bold hills capped with a coarse conglomerate, and rising to more than 

 a thousand feet, I was unable to determine its thickness. It probably 

 far exceeds two thousand feet. Certain dark shales which occur in 

 the way of interstratification contain fossil plants, but I found no 

 specimens that could be determined. 



8th. Kitau limestone. — This is an important formation, overlaying 

 the last conformably. Its name is derived from a prominent bluff 

 situated midways between Han-kau and Kiu-kiaug, called Kitau, or 



