MAMMALIA. 



31 



No. 47. [32] Megatherium Cuvieri, Desm. 



Fore-Claw (cast). In no 

 respect does the Megatherium 

 differ more strikingly from 

 existing quadrupeds of corres- 

 ponding bulk than in the vast 

 proportions of its fore-arms. 

 They were furnished with 

 prehensile feet having five 

 toes— the 2d, 3d and 4th of 

 which were armed with claws. 

 This specimen, representing the last phalanx fiud the core of the claw, is from 

 the same locality and museum as the last. Size, 11 x 6. 



No. 48. [35] Megalonyx Jeffersonii, Harlan. 



Two Claws (cast). The 

 remains of tliis huge ter- 

 restrial Sloth, so called 

 from the great size of its 

 claw, are found chiefly in 

 the Upper Tertiary of 

 Virginia, Tennessee, Ken- 

 tucky, Mississippi, Ala- 

 bama and Texas. The 

 genus was established by 

 President Jefferson in a 

 communication read to the 

 American Philosophical 

 Society, 1797, entitled "A Memoir on the Discovery of certain Bones of a Quadru- 

 ped of the clawed kind in the Western Parts of Virginia. " The Megalonyx resem- 

 bled the Megatherium in geuerj\l form and habits, but was a third smaller. The 

 originals were found in a cave in Greeubriar county, West Virginia. Size, 7x4. 



No. 49. [36] G-lyptodon (Scliistopleunim) typus, Nodot. 



Car.^pace, Head, Tail and Hind-Leg (cast). This gigantic fossil edentate 

 was a representative in Pleistocene times of the Armadillos of South America. 

 It was furnished with a huge carapace or coat of mail, formed of hexagonal 

 plates united by sutures, and constituting an impenetrable covering for the 

 upper part of the body and part of the tail. The carapace differs from that 

 of modern Armadillos in having no greaves or joints, for the purpose of con- 

 tracting or rolling up its body. The head was defended by a tesselated bony 

 casque. The tail possessed an independent dormal sheath or cuirass made 

 up of very prominent tubercles disposed in distinct whorls. This arrange- 

 ment of the component parts of the sheath permitted a slight flexibility, and 

 made the tail a formidable weapon. The bones of the leg and foot were per- 

 fectly adapted to bear the steady pressure of this enormous weight. The latter 

 is admirably contrived to form the base of a column, and at the same time to 

 allow a degree of motion required for the scratching and digging operations 

 of dasypoid animals. It is pentadactylous, four of the digits being furnished 



