48 MYLODON. 



concave, posteriorly convex. The isthmus or intermediate portion connecting the 

 lobes is only four and a half lines wide. The anterior lobe in its perfect condi- 

 tion was about fifteen lines wide, and that posterior about eleven lines. 



The collection of Col. Wailes contains two fragments of a last molar tooth (PI. 

 XVI, Fig. 20) closely corresponding to that just described, found in Mammoth 

 Ravine, Mississippi. 



Professor F. S. Holmes, of Charleston, sent for my inspection a small fragment 

 of a molar tooth of an extinct sloth-like animal, which had been discovered by Capt. 

 Bowman, U. S. A., in the sands of Ashley river. South Carolina. The specimen, 

 when first received, I supposed to indicate a species of a new genus, to which I gave 

 the name of Eiibradys antiquus^ but I now believe it to be nothing more than a frag- 

 ment of the first inferior molar of Mylodon Harlani. It is represented in two views 

 in Plate XVI, Fig. 21, a, h, and in transverse section in Fig. 21, c, which, by com- 

 parison with that of the first lower molar of Mylodon Harlani, Fig. 19, a, will be 

 found to resemble a corresponding portion sufficiently to consider it as the same. 



Dr. H. C. Perkins described a tooth and a humerus, found on the Willammette 

 or Multonah river, a tributary of the Columbia, in Oregon,^ which have been 

 referred to the Mylodon Harlani, by Professor Owen.^ 



Dr. Harlan subsequently described, and gave figures of a number of bones and 

 teeth of an extinct bradypoid animal, which were found by Mr. Koch, in associa- 

 tion with remains of Mastodon, etc., in Benton Co., Missouri.* These, Dr. Harlan 

 referred to a new genus and species luider the name of Oryctei-otherium Missoiiri- 

 ense,^ but Professor Owen, who had an opportunity of inspecting the specimens, 

 satisfactorily determined them to belong to Mylodon Harlani.^ 



The Cabinet of the Academy of Natural Sciences contains a humerus, with its 

 distal end and anterior portion of the upper half broken away, which I suppose 

 to belong to the Mylodon Harlani. (PL XIV, Fig. 3.) It was found at Big-bone- 

 lick, Kentucky, and was presented to the Academy by John P. Wetherill, Esq. 

 The specimen is an adult one, and in its details of form agrees pretty closely with 

 the corresponding bone of Mylodon rohustus ; and its measurements accord with 

 those of the Oregon specimen described by Dr. Perkins. 



The collection of Dr. Dickeson, deposited in the Academy of Natural Sciences, 

 contains a number of bones of a half grown individual of Mylodon Harlani, which 

 were discovered in association with remains of the Megalonyx and -other extinct 

 animals in the ravines in the vicinity of Natchez, Mississippi. 



The bones have lost their epiphyses, but the diaphyses are in a good condition of 

 preservation, and remain unchanged in texture, except that they are infiltrated 

 with oxide of iron. 



The specimens are as follows : — 



* Proc. Acad. Nat. Sci., VI, 241 ; Ancient Fauna of Nebraska, 10. The word Enhradys given in 

 tte former instead of Eiibradys, is a typographical error ; and the synonyme to Euhradys antiquus in 

 the latter worlc is an error resulting from its introduction in the wrong place. 



° Am. Journ. Sci. and Arts, XLII, 136. ^ Ibid., XLIY, 344. 



' lb., 69. 5 lb. ib.^ 344. 



