FOSSIL VERTEBRATES — AMPHIBIA Sol 
Anatomischer Anzeiger, Band XI, Nr. 22, 1896, p. 659) beaihiat 
the Stegocephali (the most primitive of the amphibia) did take 
their origin from a group of fishes is evident. The question to 
examine is: Which was this group?” 
‘In the Devonian preceding the Carboniferous, where the 
Stegocephali first appear, we have the following groups of fishes: 
The Llasmobranchi— including the Holocephal — Ostracodermi, 
Dipnoi, Crossopterygii and Chondrostei (this last group corres- 
ponds to the Actinopterygii of the present studies). The E/as- 
mobranchi have no dermal ossifications in the skull, they are 
therefore out of the question; the Ostracodermi have, of course, 
nothing to do with the Stegocephali; we also can exclude the 
Chondrostet represented by SLEDS Only the Dzpnoz and the 
Crossopterygu remain. 
The dentition of the Dzpnoz is already so much specialized in 
the Devonian, that it is impossible to derive the Stegocephah 
from them. We have now to consider the Cvossopterygians. The 
Crossopterygit were established by Huxley, in 1861, to contain 
the living Polypteride of Africa and the extinct //oloptychide, 
Rhizodontide, and Osteolepide, having lobate paired fins with an 
endoskeletal axis, more or less fringed with dermal rays. The 
Crossopterygui are the most typical fishes of the Devonian. There 
is no difficulty in homologizing the premawillaries, nasals, front- 
als, parietals, prefrontals, and postfrontals in the Cvossopterygi 
and the Stegocephah.’’ Here the author proceeds to prove from 
the course of the grooves upon the skulls of certain of the more 
primitive of the fishes and the amphibians, which mark the course 
of the sensory tracts of nerves in the living form, the homology 
of the skull bones of the two groups and the close connection 
that exists between them. 
In a further discussion of the homology of the ribs he con- 
cludes that the “ribs of the cldest Batrachia, the Stegocephah, are 
not homologous with the ribs of the Dzpnoz; therefore the Dzp- 
not cannot be the ancestors of the Stegocephah,” and “the Batra 
chia must have developed from the Cvossopterygit.”’ 
The Amphibia may be classified as follows: 
