140 The American Geologist. September, 1903. 
There was no direct connection between West Europe and 
Central Russia. One American species occurs here. 
Northwest and North Russia. — In this region but nine 
species are known in the upper part of the Middle Devonic 
and the lower zone of the Upper Devonic. but in places they 
form reefs of considerable extent. These belong to the fam- 
ilies Favositidae, Chaetetidac, Syringoporidae, Cyathophyllidae 
and Cystiphyllidae. 
The corals of this region have* a decided relationship with 
those of Central Russia. Compared with those of the Timan 
region there is a great difference and the conclusion is war- 
ranted that no direct connection existed between these areas 
during Devonic time. 
THE URAL-ALTAI TYPE. 
Urals. — Here we have sixty-six species distributed over a 
great area extending from north to south. The Favositidae 
and Cyathophyllidae are most abundant. The great coral hor- 
izons are in the lower and upper zones of the Lower Devonic, 
and the middle and upper beds of the Middle Devonic. 
The lowest Lower Devonic is characterized by Favosites 
(some Silurian species) and Cystiphyllidae. The upper zone 
of the Lower Devonic has such characteristic species as Cy- 
athophylluui caespitosum, C. ceratitcs, etc. 
Comparing the corals of the L T rals with those of West 
Europe and America, it is seen that the lowest Lower Devonic 
species are of the W r est European type and that in the upper 
zones of the Lower Devonic the first distinctly American spec- 
ies are met, as Favosites forbesi and Syringopora hisingeri. 
The distinctly American species increase in number in the Mid- 
dle Devonic where occur Favosites placenta, F. nitcllus, Sy- 
ringopora perelegans, S. nobilis, S. tabulata and Emmonsia 
hemispherica. In the Upper Devonic, corals are rare and the 
data for comparison are not satisfactory. 
"We recognize that the Devonian corals of the Urals have 
in general a great resemblance to those of West Europe, al- 
though here also appear strange elements as local and Amer- 
ican forms. These occurrences seem to show that between the 
Devonian of the Urals and that of North America there was a 
less decided connection than between the former and West 
Europe." (p. 167.) 
