1903.] Brown, A New Genus of Ground Sloth. 571 



1900. Roth and Smith Woodward identify Neomylodon with Grypo- 

 therium, which they hold to be generically distinct from M. 

 robustus, etc. (presumably from Lydekker's second group as 

 a whole, and therefore by inference from the typical Mylo- 

 cion). 



1900. Ameghino objects to the use of Grypotherium on the ground 

 that it was fotmded on the type species of Mylodon, which 

 he erroneously supposes to be M. darwini. 



The type of M. harlani should be in the Columbia University- 

 Museum, but has been lost or mislaid. A cast of it, in the 

 Museum of Williams College, has been loaned to the writer 

 through the kindness of Professor Cleland. Comparison of 

 this cast with a series of skulls of the subsequently described 

 genera and species shows that M. harlani is not congeneric 

 with G. danvini and is nearest, on the whole, to M. robustus 

 This classic species, therefore, is properly referred to Mylodon 

 and the characters of the genus may be derived from it. 

 Grypotherium appears to be a valid genus, but its name may, 

 perhaps, be antedated by Glossotherium. Lestodon is a valid 

 genus; Pscudolestodon is not separable from Mylodon. 



Paramylodon nebrascensis, sp. nov. 



Skull. 



Basal Vieiv. — The upper dentition comprises eight teeth 

 set in two diverging rows at such an angle that the space 

 separating the two anterior is twice that separating the two 

 posterior teeth. 



The first molar is the largest and simplest of the series, hav- 

 ing the form of an elongated ellipse, with the longer diameter 

 twice that of the shorter. It is greatly curved antero-posteri- 

 Orly, the convex surface in front; the sides are straight. The 

 longest diameter of the tooth is parallel to the dental series, 

 and the outer side forms a line with the posterior teeth. The 

 crown is worn deepest in the middle. 



The second molar is bilobed; the anterior lobe stands at 

 right angles and the posterior lobe oblique to the series. The 

 tooth is triangular, with the angles rounded. The anterior 

 side is gently convex; the inner side is marked by a deep 



