230 



Annals of the Carnegie Museum. 



We have the milk-teeth of M. americanum, both erupted and immature, 

 before us for comparison, and I cannot bring myself to see that this 

 fragment could possibly be so referred. The fragment shows in the 

 first place such wear as to indicate that the animal was not very 



Fig. 4. Fragment of tooth of Proboscidean (?) CM. Cat. Vert. Foss., No. 

 1 1033/. Natural Size. 



young. The most remarkable feature, however, is the corrugated 

 surface of the outer enamel, which reveals deep stride or irregular 

 grooves and between them quite elevated rugae, or elevations, which 

 tend to converge at the extremity of the cusp. I herewith give a 

 sketch of this fragment. It may be that some of my fellow-students 

 can indicate to me what it may represent, but thus far I am unable to 

 identify it with anything which I have found figured or described in 

 the literature of the subject. Some of the older writers would, I 

 imagine, have erected a genus and a species upon this thing, but we 

 are coming in these later days to act more prudently and with greater 

 reserve. Even the reference to the Proboscidea may be in error. 



Suborder PERISSODACTYLA. 



Family EQUID.E. 



Genus? sp.? 



There is an upper molar (No. 11032) somewhat broken, (M^?) 

 which seems to be referable to, if not the same as, Equus rectidens 

 H. Gerv. & Ameghino. {Cf. Ameghino, Los Mamiferos Fosiles de la 

 RepuUica Argentina, p. 505, PI. XXVII, fig. 8.) We also have the 

 lower molar of a horse, which may, or may not, belong to the same 

 species, but which is indeterminable, the tooth being badly injured 



