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ANNALS NEW YORK ACADEMY OF SCIENCES 
to-day.” Ameghino has repeatedly insisted upon the great antiquity of the 
armadillos, and that they represent very nearly the central stock from which 
the edentate families are descended. 
3. All the ungulates are braehyodont; most of them belong to the 
Notungulata, a group proposed by Roth which is not represented in the 
northern world. The animals regarded by Ameghino as ancestral to the 
Ancylopoda or clawed Perissodactyla and to the Equine Perissodactyls, are, 
according to Roth, early stages in the evolution of the Notungulata and have 
nothing to do with Perissodactyls. 
4. The so-called Creodonts of the early South American faunse (Sparas- 
sodonta) are not really related to the true Creodonts of the northern hemi¬ 
sphere, the resemblances being due to parallelism. Sinclair has demon¬ 
strated this very clearly as regards the Sparassodonta of the Santa Cruz 
fauna. 
The reviewer notes with regret that Dr. Roth does not discuss in any 
detail the l'elations or comparisons between the apparent Condvlarth and 
Multituberculate element of the Notostylops fauna and the Condylarths and 
Multituberculates of the Puerco, Torrejon and Cernaysian faunae of North 
America and Europe. These groups, although imperfectly known, appear 
to afford the most important means of comparison with the basal Eocene 
mammal faunse of the northern world. Roth is apparently unaware that 
the absence of rodents is also a marked feature of the northern basal Eocene 
faunse. Nor does he take into account the relatively advanced stages of 
evolution in the Notungulate groups of the Notostylops fauna as compared 
with anything to be found in the Puerco-Torrejon or Cernaysian. These 
data appear to us to be important parts of the evidence, which we trust may 
be duly discussed and considered later. 
II. The Pyrotherium Fauna. 
There has been a good deal of confusion between the Pyrotherium 
fauna and the preceding Notostylops fauna, which is not yet cleared up 
satisfactorily. The most characteristic genus is Pyrotherium, and, as 
evidence of more recent age than the Notostylops beds, no association of 
Dinosaur teeth with this fauna has been demonstrated. The formation is 
provisionally placed by Roth in the Eocene. 
III. The Patagonian Tuff Formation. 
Under this Dr. Roth includes both the marine Patagonian and the 
terrestrial Santa Cruz beds. He agrees with Ameghino’s more recently 
