94 PROCEEDINGS OP THE ACADEMY OP 



The three last species, here given as C.psaltria, O. mezicana, and C. Columbi- 

 ana, and so given also generally by modern authors, I regard as very probably 

 not belonging to this genus. In my opinion these little birds are more nearly 

 related to the group given by Dr. Sclater as Cyanospizinse, and possibly are 

 entitled to generic distinction. 



June 6th. 



Mr. Cassin, Vice-President, in the Chair. 



Twenty-one members present. 



The following papers were presented for publication : 

 " Descriptions of new species of Fossils from the Marshall Group of 

 Michigan, &c." By Alexander Winchell. 



" Descriptions of new species of Eocene Tertiary Fossils." By R. 



P. Whitfield. 







Dr. Leidy exhibited some bones and teeth of Horses from California and 

 Oregon, recently submitted to his examination by Prof. J. D. Whitney. He 

 stated that fossil remains of Horses had been found throughout the length 

 and breadth of the North American continent. They had been obtained from 

 the frozen cliffs of Eschscholtz Bay, in Arctic America, and from Honduras in 

 Central America; from New Jersey, Pennsylvania, Maryland, Virginia, North 

 and South Carolina, Georgia, Kentucky, Mississippi, Louisiana, Missouri, Ne- 

 braska and Texas. Many of the remains are undistinguishable in anatomical 

 character from corresponding bones and teeth of the domestic horse ; others 

 are comparatively large, though not larger than in the largest variety of the 

 latter, but their molar teeth exhibit a more complex folding of the enamel 

 than is seen in the domestic horse. Dr. L. considers it probable that the 

 fossils represent several extinct species, all differing from the living horse, 

 though this was not a matter of demonstration. 



Most of the remains from California, among them an entire skull, are un- 

 changed in appearance, and are undistinguishable from corresponding parts 

 of the Mustang, or recent Indian Horse of the West, though taken from au- 

 riferous gravel a considerable depth from the surface. 



Among the California specimens are several molar teeth having more the 

 general appearance of true fossils than the others, though they are also but 

 slightly changed. Two of them are second upper molars from different indi- 

 viduals, of more robust proportions than any of the recent looking specimens, 

 and equal in this respect to the corresponding teeth found anywhere. One 

 of the teeth was taken from auriferous clay at a depth of thirty feet below 

 the surface, in Tuolumne County, and is slightly infiltrated with oxide of 

 iron. The other was obtained from a bed of asphaltum, in company with a 

 last lower molar, near Beuna Vista Lake, and is impregnated with bitumen. 

 These two upper molars, strongly resembling each other, differ from the more 

 recent looking specimens, and from the corresponding teeth of the domestic 

 horse, in the remarkable degree of simplicity of the enamel folding, as seen 

 on the triturating surfaces. They differ in another circumstance, which is 

 perhaps accidental, or at least was dependent on the peculiar character of 

 the food, that is to say, the triturating surface, in both specimens, is remarka- 

 bly flat, whereas, in the horse ordinarily it is worn into two transverse hills. 

 Dr. L. was disposed to view these teeth as representing a species different 

 from any heretofore indicated, and proposed for it the name of Equus occi- 

 dentals. The measurement of the specimens are as follows : Anteropos- 

 terior diameter of triturating surface 14| lines, 1 5^ lines; transverse diameter 

 of do. 12 lines, 13J lines. 



[June, 



