152 JATURAL SCIENCE [September 
THe SoutH AMERICAN EDENTATE MAMMALS 
HAvinG satisfactorily demonstrated the ancestral position of 
the Ganodonta to the modern American Edentata, Dr Wortman 
goes on to observe that if this be true, “it follows that all the 
South American edentates must have been derived from the 
North American Ganodonta, since their earliest appearance in 
South America does not antedate the Santa Cruz epoch. In this 
formation they appear suddenly in great numbers ‘and variety, 
without apparently any announcement in the older Pyrothervwm 
deposits. This fact in itself would seem to indicate that they 
were migrants from another region, and while we are as yet unable 
to place these deposits in the time-scale with accuracy, it is yet 
highly probable that the Santa Cruz beds are not older than our 
North American Oligocene. In North America the Ganodonta 
appear in the very earliest Puerco deposits, and continue without 
interruption into the Bridger, where they disappear. No evidences 
of them have up to date been detected in the Uinta or White 
River beds. 
“ Now it is currently believed by geologists that no land con- 
nection existed between North and South America from the close of 
the Cretaceous to the close of the Miocene, when an extensive land 
bridge was formed. I am not familiar with the geological evidence 
upon which the conclusion rests, but if one is permitted to judge 
from the subjoined statements of Mr F. C. Nicholas, it is at the 
very least open to question. It is, of course, possible that the 
Ganodonta may have reached South America by way of Europe, 
Africa, and Antarctica, but on the whole it seems infinitely more 
probable that there was a land bridge of short duration during 
Eocene time between North and South America, and that they 
reached their destination in this way, than by the questionable and 
circuitous route just mentioned. If they gained entrance into 
South America by the European-African route, it seems indeed 
strange that they should have left no remains in the later Tertiaries 
of Europe. With the exception of a single specimen of Calamodon 
ELuropaeus, from deposits corresponding with the Wasatch in age, all 
traces of the American Edentata are absent in Europe, Asia and 
Africa.” 
To the first paragraph in this quotation no exception can be 
taken. With regard to the second, we have not the pleasure of 
being acquainted, either personally or by his writings, with Mr F. 
C. Nicholas, who may be a most excellent person, but the rambling 
extracts from a letter of his, which Dr Wortman prints in a foot- 
note, can scarcely affect the problem of a land connection between 
the two Americas in early Tertiary times. Apart from this, the 
