Mineralogy and Geology. 129 
dinary cubic cleavage; while in the fluors just mentioned the perfect 
octahedral or normal cleavage remains preéminent. 
The fact observed by Dr. Torrey, that the miueral developes a cubic 
structure by heat, has an important bearing in the consideration of this 
subject, and would seem to favor its being a case of dimorphism. But 
if it were a case of dimorphism, a difference between the specific gravity 
of this variety and that of ordinary galena would probably be observed : 
find, however, that the Lebanon county mineral has a density of 7°63, 
Which, although somewhat above that of ordinary cubic galena (7°568), 
oes not offer any very great confirmation of its dimorphic. character, 
especially as most works on mineralogy give the density of galena as from 
72 to 7°6. If a mass of this octahedral galena could be heated in a close 
Vessel at a red-heat, without decomposition, until the cubic cleavage was 
_ 2. Discovery of Remains of vertebrated animals provided with feathers, 
in a deposit of Jurassic age ; Cresta, Nov. 5th, 1862).—We t 
from the Bibliotheque Universelle the following résumé of the publica- 
ons made . Wagner and H. von Meyer on the feathered fossils 
Tecently discovered at Solenhofen, 
fou . principal specimen, the object of these communications, is to be 
n 
of P. 
W 
in the beautiful collection of fossils belonging to Mr. Haberlein 
emist seems to put full confidence. H. von Meyer has since then 
that of Archeopteryz lithographica. ; : i 
Bad goo of the animal made known by these curious fragments is 
u 
. '¢ specimen of Mr. Haberlein is the one which furnishes the prin- 
“ipal data for this discussion. It is an incomplete skeleton, lacking the 
ane the neck and the terminations of the anterior members. The 
of hers are preserved toward the base of the wings and about the region 
™ the tail. “According to the before-mentioned report, it is this latter 
oh Which is the most characteristic. The sacrum recalls the form of 
of a Pterodactyl; the tail which is six inches long is composed of 
AM. Jour. Sc1.—grconp Sunres, Vou. XXXV, No. 108.—Jan., 1963. 
iy 
