45 



A specimen of coal exhibiting pure anthracite, mineralized char- 

 coal and a material strongly resembling coke in exterior charac- 

 ters, was also among the objects commented on. The tendency of 

 the anthracite portion to a crystalloid arrangement was also re- 

 marked. 



Mr. Bulfmch read a report on the casts of fossil footsteps 

 from Cheshire, England, lately presented to the Society by 

 Mr. Archer of Liverpool. 



He gave an account of the researches of Professor Owen as de- 

 tailed in a communication to the Geological Society of London in 

 the present year, by which the Professor has been led to the con- 

 clusion that the footmarks of the Keuper sandstone of Germany, the 

 Cheirotherian impressions of Hessberg, those of the Warwick sand- 

 stone, and those of Cheshire, of which we have the casts, are those 

 of an animal of one and the same genus, and of the Batrachian 

 family. This result was obtained from an examination and com- 

 parison of teeth, found in the German sandstone, with others found 

 in England, and particularly from sections of the teeth viewed mi- 

 croscopically, disclosing a structure entirely unknown heretofore, 

 in which the enamel of the outer portion of the tooth is diffused 

 through the interior substance in folds, exhibiting a labyrinthine 

 appearance, upon a cross section. From this structure, the Pro- 

 fessor has formed the name of " Labyrinthodon," to designate the 

 animals of the fossil footsteps heretofore designated by the various 

 names of Cheirotherium, Salamandroides, Mastodonsaurus, &c. 



Dr. Storer, through Dr. Abbot, presented a rare variety 

 Phrynosoma cornuta from Texas, together with a specimen 

 of Trionix ferox, from the Hudson river sent to him by Dr. 

 Wright. 



It was first described in 1771, in the Philosophical Transactions, 

 and afterward described and figured by Lacepede. The present 

 specimen is young, as the old ones are covered with tubercles. It 

 has no undershell. 



Dr. C. T. Jackson exhibited specimens of the compact 

 tin ore from New Hampshire, and one of Chlorophillite, a 

 new mineral, discovered in the town of Unity, N. H., which 



