Trans. N. Y. Ac. Sci. 20 Nov. 12, 
Prof. J. S. NEWBERRY read a paper on 
THE RELATIONS OF DINICHTHYS, AS SHOWN BY COMPLETE CRANIA 
RECENTLY DISCOVERED BY MR. JAY TERRELL, IN THE HURON 
SHALE OF OHIO. 
Drawings of these crania were exhibited. They showed that the head 
was shorter and broader than was formerly supposed, and confirmed 
the views expressed in the Report of the Geology of Ohio, that 
Dinichthys was closely allied to Coccosteus, but was a hundred times 
larger. The cranium of Dinichthys was strongly arched in life, but 
is flattened by compression in the fossil state. It is then triangular in 
outline, nearly three feet broad behind, and two feet long. The brain 
box was partly cartilaginous, but was enclosed in strong, continuous 
plates of bone. The fin rays and some of the vertebrz were ossified. 
The head was articulated with the body by the strongest, most com- 
plex and complete osseous joint yet found in nature. 
November 12, 1883. 
LECTURE EVENING. 
The President, Dr. J. S. N EWBERRY, 1n the Chair. 
Fifty-eight persons present. 
The PRESIDENT stated that the crystals of a mineral from 
Laramie City, presented at the last meeting by Mrs, WeLp, 
had been examined by Prof. Brusu, of New Haven, who re- 
ported that they appeared to consist of aragonite, although 
enclosing some minute rhombohedral crystals, apparently of calc- 
spar; but that he had never seen aragonite crystals possessing 
the same bevelled edges. The variety was entirely new. 
Dr. Hupsparp W. MITCHELL then delivered a lecture, illus- 
trated with diagrams and stereopticon, upon 
THE SUCCESSION OF ANIMAL LIFE ON THE GLOBE. 
November 19, 1883. 
SECTION OF GEOLOGY. 
The President, Dr. J. S. NEWBERRY, in the Chair. 
Forty persons present. 
A Communication was received from Dr. H. CaRRINGTON BoL- 
TON, of Hartford, Conn., presenting two specimens of a minute 
gasteropod, which had been recently found in great numbers upon 
