1851.] 329 



December XQtli. 

 Vice-President Wetherill in the Chair. 



A letter was read from Dr. D. Leasure, dated Lewistown, Pennsyl- 

 vania, December 5th, 1851, announcing the transmission of the skin of 

 an adult American Black Bear, for the Museum. 



Dr. Le Conte presented for publication in the Journal, the conclusion 

 of his paper entitled " An attempt to classify the Longicorn Coleoptera 

 of America North of Mexico." Referred to the Committee on the former 

 portions of the paper. 



Dr. Leidy read a paper from Mr. Charles Grirard,- intended for publi- 

 cation in the Proceedings, entitled "Notice of twelve new genera of 

 exotic Planarise, by Charles Girard," which was referred to Mr. Lea, Dr. 

 Ruschenberger, and Dr. Leconte. 



Mr. Cassin read a paper, intended for publication in the Proceedings, 

 entitled " Description of Birds of the genera Laniarius, Dicrurus, Grau- 

 calus, Pipra, and Picus, specimens of which are in the Academy of 

 Natural Sciences of Philadelphia." Referred to a Committee consisting 

 of Dr. Fisher, Dr. Wilson, and Dr. Watson. 



Dr. Leidy exhibited several fossils, from the Green Sand of New Jersey, which 

 he characterized as follows : 



Chei.onia geand^va, Leidy. 



Proposed upon three vertebral plates from the Green Sand of New Jersey, pre- 

 sented to the Academy by Mr. Wetherill. 



One of these has its anterior extremity broken off, but the length of the frag- 

 ment is greater than the breadth ; its form has been quadrilateral, and it was pro- 

 bably the first vertebral plate. Length 2 in. 8 lines ; breadth 23 lines. 



A second plate is broad hexahedral, the two lateral sides equal and shorter 

 than the anterior, which is concave, and the posterior which has the stump of a 

 pointed process. 



Length 26 lines ; breadth 32 lines ; thickness 5i lines. 



The third plate is hexahedral, sinuated in front, with a pointed process behind. 



Length with process 28 lines ; breadth 28 lines. 



Trionyx priscus, Leidy. 



Indicated by a fragment of the proximal extremity of a costal plate, from the 

 Green Sand of New Jersey. 



Thickness of plate 3i lines, with the rib proper five lines. 



The attention of the members was also directed to a fossil cranium from the 

 Eocene of Nebraska, from the collection of Dr. D. D. Owen, which was charact- 

 erized as follows : 



Machatrodus priM/^vus, Leidy and Oioen. 



Established upon a mutilated cranium, one-fourth less in size than the panther, 

 Felis concolor. 



The greater portion of the canines is broken away, but suflScient remains of 

 that of the right side to indicate that it was long, compressed in form, and den- 

 ticulate upon its concave edge. 



