514 Zoological Proceedings oj" Societies. 



species. In the other classes and orders, equally striking diiFerences are 

 observable. 



On the other hand, the marine formations are destitute of the charac- 

 teristic fossils of the fresh-water formations, viz. birds, terrestrial and 

 fresh-water reptiles, shells and vegetables. The authour, in short, con- 

 cludes that a comparison of the living inhabitants of our lakes and rivers, 

 with those of the ocean, would not offer more striking discrepancies. 



June 20. — An extract was read of a letter from Samuel Hobson, Esq., 

 to Dr. Roget, F.G.S., Sec. R.S., &c. (dated at New Orleans, 6th April, 

 1827,) and enclosing an account of some gigantic bones, by Samuel 

 W. Logan, M.D. 



The place where these bones had been found is not mentioned; bat at 

 the date of the letter, they were exhibited publicly at New Orleans. Dr. 

 Logan describes them as consisting of one of the bones of the cranium^ 

 fifteen or twenty vertebrce, two entire ribs and a part of a third, one thigh- 

 bone, two bones of the leg, and several large masses of a cancellated 

 structure. 



The cranial bone was twenty feet and some inches in its greatest length, 

 about four feet in extreme width (for the bone tapers to a point), audit 

 weighed twelve hundred pounds. Dr. Logan inclines to think that this 

 is the temporal bone. 



The vertebra, consisting of a body, oblique, transverse, and spinous pro- 

 cesses, gave sixteen inches as the mean diameter, and twelve inches as the 

 depth of the bodies; while the passage for the spinal cord measured nine 

 inches by six. The spinous processes stand off backwards and down- 

 wards, fourteen inches in the dorsal, and somewhat less in the lumbar 

 vertebrce, three of which latter are entire. 



The ribs, well formed and in a perfect state of preservation, measured 

 nine feet along the curve, and about three inches in thickness. 



The thigh-bone, measured in length, gave only one foot six inches, but 

 is very thick. The bones of the leg are of similar dimensions, but per- 

 haps a little more slender. 



It had been conjectured that the animal to which these remains be- 

 longed was amphibious, and perhaps of the Crocodile family ; and the 

 conjecture appeared to Dr. Logan to be justified by the great length and 

 flatness of the head (judging from the single specimen of the cranial bone), 

 and the shortness of the limbs. It was also supposed that the animal, 



