360 Zoological Siimmart/ of Extinct and Livinfj Animals^ cj-c. 



Genus 3.— Mylodon, Owen. {Megalonyx, Harlan,* Orycter other turn, 

 Harlan.)t 



Dentes — discreti, superiorum anticus subellipticus, e reliquis modicQ 



remotus ; secundus ellipticus ; reliqui trlgoni pagina interna sulcata : 

 inferiorum anticus ellipticus ; penultimus tetragonus ; ultimus maxi- 

 mus, bilobatus. Pedes aequales : manus pentadactyli ; podarii tetra- 

 dactyli ; utrisque digitis duobus externis muticis, reliquis falculatis : 

 falculae magnce, semiconicee, insequales. Caput fcmoris ligaraento 

 rotundo impressum : tibia et fibula discretce : astragalus pagina an- 

 tica supra complanata : calcaneum longum, crassum. 



Species 1. — Mylodon Darwinii^ O. Maxilla inferior symphyse longiore 

 angustiore ; molaris secundus subellipticus ; ultimus bisulcatus, sulco 

 in tern o angulari. 



Species 2. — Myl. Harlani, 0. {Megalonyx laqueatuSj Harlan, Oryctero^ 

 therium Missouriense, Harlan.) Maxilla inferior symphyse breviore, 

 latiore ; molaris secundus subquadratus ; ultimus trisulcatus, sulco 

 interne bi-angulari. 



Species 3. — Myl. Robustus, 0. Maxilla inferior symphyse breviore, 

 latiore ; molaris secundus subtrigonus ; ultimus trisulcatus, sulco 

 interno rotundato. 



Genus 4. — Scelidotherium, Owen. (Syn. Megalonyx, Lund.)+ 



6-5 



Dentes — aut contigui aut intervallis sequalibus discrcti j superiores 



trigoni; anticus inferiorum trigonus, secundus et tertius subcora- 

 pressus, pagina externa sulcata ; ultimus maximus, bilobatus. 

 Caput femoris ligamento tereti impressum ; tibia et fibula discretse. 

 , Astragalus antice duabus excavationibus. Calcaneum longum, cras- 

 sum. Falculaj magna?, semiconicse. 



Species — Scelidotherium Leptocephalum, 0. 



Seel. Cuvieri, O. (Syn. Meg. Cuvieri, Lund.) 

 Seel. Bucklandi, O. (Syn. Meg. Bucklandi, Lund.) 

 Seel. Minutum, O. (Syn. Meg, Minutus, Lund.) 



* The lower jaw described by Dr Harlan, loc. cit. p. 334-335. It is erro- 

 neously ascribed to the Megalonyx laqueatus. 



t Proceedings of the American Philosophical Society, Vol. ii. No. 20, p. 109. 



J I am in doubt whether the term Platyonyx, subsequently proposed by Dr 

 Lund, be really intended to apply to the animals of the genus Scelidotherium, see- 

 ing that the breadth of their claw -bones is equalled by the height, and vastly ex- 

 ceeded by the length, of the same : it would be very descriptive of the broad 

 ungual bones of the Glyi>todon, and its congeners. 



