MOODIE: MAZON CREEK, ILL., SHALES. 327 
amphibians differ from the Canadian species in the almost 
total absence of any scaly covering such as occurs in Den- 
drerpeton and Hylerpeton, although Micrerpeton has very 
small scales over the body and tail. Furthermore, the Cana- 
dian species are more terrestrial than those from Mazon Creek, 
which, judging from their form, were either entirely aquatic 
or only partially terrestrial. The size of the members of the 
two faunas differs in no great degree. Large and small mem- 
bers are found in both localities. The Joggins: Amphibia are 
hardly well enough known to judge their relationships other 
than those of an ordinal or family rank. These relations a 
be given in another paper. 
The Linton fauna, which is more fully described in another 
paper, is quite unlike the Mazon Creek fauna. This is evident 
by the absence of branchiosaurian forms from the Linton 
deposits and by the presence of the legless Microsauria and 
the Proteid form Cocytinus, which is paralleled’ by Hvierpéton 
in the Mazon Creek fauna. The limbed Microsauria also differ 
in a marked degree, in that the Mazon Creek forms’ havea 
strong tendency toward the Reptilia, as illustrated in the 
Amphibamide, Amphibamus and Ceplhalerpeton. The Linton 
fauna shows a wide divergence of types, illustrating different 
phases of amphibian development, and in the tendency of 
certain groups, such as the families Tuditanide and Macrer- 
petidz, to approach the Stegocephala proper and through them 
certain of the stegocrotaphous reptiles. The Linton fauna is 
distinctive too in the abundant presence of such ‘highly de- 
veloped swimmers as Cstocephalus, Ptyonius, Phlegethontia 
and Ctenerpeton, and as such is interesting in displaying 
parallel development of the same structures in forms which 
are really widely separated in structure. 
The fauna of the Cannelton slates is not very different from 
that of Linton, and the remarks made concerning the relation- 
ship of that fauna to the Mazon Creek fauna will also apply 
with reference to the Cannelton fauna. Outside of these four 
deposits, there are several minor deposits which have fur- 
nished amphibian remains, none of which agreé in any essen- 
tial respect with the Mazon Creek fauna. ‘Attention has al- 
ready been called to the fact of the occurrence of the embolomer- 
ous forms in the Mazon Creek, the Pitcairn, Pa., the Kansas, 
and the Salt Creek, Illinois, faunas. 
