Geology and Natural History. 68 
specimens, and to take for study the thin sections of the rocks 
which had been made—more than a thousand in number—and will 
prepare a report upon them for publication in the 40th Parallel 
serie 
8. Geological Sketch of the State of Missouri, illustrated by 
- by Gro. C. Swatiow, A.M., M.D., late Sta eologist, 
and Prof. Agric., Geol. and Bot. in the Univ. of the State of Mis- 
souri, 10 pp. large 4to. St. Louis, 1873. (R. A. Campbell.) 
This sketch by Professor Swallow presents a brief review of the 
Geology of the State of Missouri and is accompanied by a colored 
section and a colored geological map. The section makes the 
third and fourth magnesian limestones, with the intervening sand- 
stone, equivalents of the Primordial. 
9. Das Elbthalgebirge in Sachsen of Dr. Gerxitz.—The fifth 
number of Part II has been issued by the publisher, T. Fischer, 
of Cassel. It contains the Gasteropods and Cephalopods, with 
plates 29 to 36 inclusive. 
10. Preliminary Notice of Chondrodite Crystals from the Tilly- 
Foster Iron Mine, Brewster, N. Y.; by Epwarv 8. Dana.—The 
occurrence of chondrodite in large quantities at the Tilly-Foster 
Iron Mine has already been described by Professor Dana in an 
article upon “ Serpentine Pseudomorphs,” published in the two pre- 
ceding numbers of this Journal. In addition to the common mas- 
Sive variety of the species, and that occurring in large coarse crys- 
tals, there have been found also, though very rarely, some small 
bu tting of the most accurate measure- 
a These crystals are of a rich garnet-red color, with abso- 
ut 
planes. The special interest of chondrodite arises from its relation 
to, or more properly identity with, the Vesuvian humite, whose re- 
Most part, to the second type, : 2 
ber of crystals I have identified also representatives of the third 
type. A few angles will show how close is the resemblance to 
a (The letters for the planes are those used by vom 
th, 
Il Type. III Type. : 
Humite (v. Rath). Chondrodite (E.§. Dana). Humite. Chondrodite. 
1 
sre ya ieee 
A:tr = 135° 18” 135° 19’ ‘Acie = 111° 5) 111° 44’ 
A:}tr 125° 49% =125° 50° A: ¢ = 109° 28’ Lb 
mre. 300" te" 100" A:}4= 125° 16’ 125’ 13 
Mit 999° 99/5: 128° 98 
The planes, which occur constantly, are the same that are found 
on humite, and the kind of hemihedrism is the same. This is true 
