FOSSIL MAMMALIA. 67 



The next notice of the Megalonyx which I have consulted, in the hope of 

 meeting with additional and more precise information as to its real generic charac- 

 ters, is an account given by the learned Professor Doellinger,* of some fossil bones, 

 collected by the accomplished travellers Spix and Martius in the cave of Lassa 

 Grande, near the Arrayal de Torracigos, in Brazil. In this collection, however, it 

 unfortunately happens that there are no teeth, but only a few bones of the extremi- 

 ties, including some ungueal phalanges, which Professor Doellinger concludes, 

 from their shape, the presence of an osseous sheath for the claw, and the form of 

 their articulation, to belong, without doubt, to an animal of the Megatherioid kind, 

 about the size of an Ox. He particularly states that they are not bones of an 

 immature individual; but that they agree sufficiently with Cuvier's descriptions 

 and figures of the Megalonyx to be referred to that species of animal (zu dieses 

 thierart ;) and he adds, what is certainly an interesting fact, that the fossils in 

 question form the first of the kind that had been discovered out of North 

 America. 



Subsequently to the discovery of these bones, and of those of the Megalonyx 

 laqueatus above alluded to, the remains of another great Edentate animal were 

 found in North America, and were deposited in the Lyceum at New York ; among 

 these is a portion of the lower jaw with the whole dental series of one side. It 

 is thus described by Dr. Harlan. 



" The fragment I am now about to describe is a portion of the dexter lower 

 jaw of the Megalonyx, containing four molar teeth ; three of the crowns of these 

 teeth are perfect, that of the anterior one is imperfect. These teeth differ con- 

 siderably from each other in shape, and increase in size from the front, the fourth 

 and posterior tooth being double the size of the first, and more compressed 

 laterally ; it is also vertically concave on its external aspect, and vertically con- 

 vex on its internal aspect ; the interior or mesial surface is strongly fluted, and it 

 has a deep longitudinal furrow on the dermal aspect, in which respect it differs 

 from the tooth of the M. laqueatus previously described by me, of which the 

 dermal aspect is uniform, but to which, in all other respects, it has a close resem- 

 blance. I suppose it therefore probable, that this last may have belonged to the 

 upper jaw. The three anterior molars differ in shape and markings : they are 

 vertically grooved, or fluted, on their interior and posterior aspects, a transverse 

 section presenting an irregular cube. The length of the crown of the posterior 

 molar is two inches : the breadth about five-tenths of an inch : the length of the 

 tooth is three inches and six-tenths. The diameter of the penultimate molar is 

 eight-tenths by seven-tenths of an inch. The length of this fragment of the 

 jaw-bone is eight inches and four-tenths ; the height three inches and six-tenths : 

 the length of the space occupied by the alveolar sockets five inches and eight- 



* Spix and Martius, Reise in Brazil, Band ii. p. 5. 



