The St'Oj>e of Paleontology. — Wilhains. 163 
But in Europe, where the statistics are abundant and clear, and 
so far as evidence bore upon the fact, also in Eussia. Asia, and 
British America, the Cuboides fauna is the natural successor of 
the middle and lower Devonian of those regions. 
Mr. AVhiteaves. in his recent studies of the British American 
Devonian along the McKenzie River valley, adds man}- points of 
■confirmation of this view, as in some species like SfriiigocrplKf/iis 
Burtln!, which had not heretofore been known in America, but 
were characteristic of certain middle Devonian of Europe. 
These purely paleontological investigations had proved, with a 
high degree of certainty, that, relatively speaking, the Tully 
limestone marks a chronological point in the strata which within 
relatively small limits may be said to be chronologically and not 
merely taxonomically the same as the Cuboides zone of Enrope 
and Asia. and. second, that the upper Devonian faunas of these 
several regions are more closeh' allied than the typical upper De- 
vonian fauna of New York is to its typical middle Devonian fauna 
of the same area. 
This is a very important conclusion, and the princii>le involved 
is of vast importance in further studies of comparative nature. It 
makes necessary the tracing of the geographical distribution of 
species in order to get accurate data for the interpretation of their 
geological succession. 
As confirmation, however, of the above conclusion, there has 
recently appeared a paper by Steinmanand Ulrich on the '-Devon- 
ian fossils of Bolivia,' in which we are shown the origin of the 
middle and lower fauna of New York and eastern America. 
By the comparison of the Devonian faunas of Bolivia, the 
Andes, Brazil. Falkland islands and South Africa, Ulrich reaches 
the conclusions as to their natural affinities with each other, and 
with the lower and middle Devonian faunas of eastern North 
America, and as remarkably distinct from the corresponding 
faunas of Europe and northern Asia. 
Not only does the presence of peculiar species link together 
these several regions and separate them from the northern set of 
regions. l)ut some of the more characteristic species of the 
southern hemisphere type, as Vitnllna and LcpfocdHa, are abun- 
dant and common to many localities and of higher range in the 
southern hemisphere and are rare or confined to lower horizon in 
