No. 453-] 



NOTES AND LITERATURE. 



677 



Origin of the Large Mammals of North America.— M. Grant^ 

 discusses the old continental connections of North America with the 

 Old World and with South America. Most important is his idea 

 about the old " Beringian connection" between northeastern Asia 

 and northwestern America, which, according to him, was not a con- 

 tinuous one in time, as generally accepted (from the upper Creta- 

 ceous to the lower Pleistocene). Grant believes that it existed in 

 the lower Eocene, lower Oligocene, middle Miocene, upper Pliocene 

 and lower Pleistocene, but that it was interrupted chiefly in the mid- 

 dle and upper Eocene, upper Oligocene and lower Miocene. The 

 evidence supporting this assumption is not very convincing, since in 

 part it 1 ly be founded only upon a deficiency in our knowledge of 

 the fossil Mammals both of the Old and the New World. Moreover, 

 the geographical distribution of marine animals does not support this 

 view, at least as far as it refers to the older Tertiary. There is 

 hardly any trace of an exchange of faunas between the northern 

 Pacific and the northern Atlantic by way of the Arctic basin during 

 earlier Tertiary times, the similarities in the faunas of these oceans 

 generally being clearly indicative of a very recent connection of 

 them. There is either no resemblance at all, or very close affinity 

 of forms generally amounting to specific identity, the latter cases 

 being found among forms that are apparently circumpolar cold-water 

 types of recent origin. 



It shall not be denied that there are a few cases of allied or even 

 identical species in both oceans belonging to more temperate cli- 

 matic conditions (for instance, resemblances of Japanese and Medi- 

 terranean forms) which might possibly indicate a former interruption 

 of the Beringian bridge in the beginning of the later half of the Ter- 

 tiary, but this point needs further elucidation. 



A. E. O. 



Walther's Solnhofen Fauna.^— One of the most philosophical 

 iscussions of extinct Faunaj is this essay by Dr. Walther, which 

 ^rms part of the Hteckel Anniversary Volume. The geological 



