516 MOODIE. [Vot. XIX. 
same as the supratemporal cross-commissure of Amia. It 
will be noticed that the main canal in the Stegocephala is 
the infraorbital canal as it is in Amia and Polyterus (Figs. 
2, 3). In the Stegocephala likewise, the main canal always, 
or almost always, cuts the epiotic as it does that element in 
the fishes which Baur would correlate with the epiotic. 
There are five suborders of the extinct Amphibia (9) in 
nearly all of which there have been detected evidences of the 
lateral line system. ‘The extinct Amphibia of the pre-Juras- 
sic are known as the Stegocephala and the five suborders of 
this group may be designated: the Branchiosauria, the Micro- 
sauria, the Aistopoda, the Temnospondylia and the Stereos- 
pondylia. In all of these suborders, with the exception of the 
Aistopoda, the lateral line system has been observed. The 
canals are more clearly preserved on the skulls of the Stereo- 
spondylia than in any of the other groups, the reasons for 
which we will consider later. 
The Branchiosauria are known by numerous individuals of 
several species found abundantly in Europe in the Upper Car- 
boniferous and Permian, and by a single species founded on a 
single well-preserved specimen from the Carboniferous of Illi- 
nois. [he Branchiosauria are the best preserved of all of the 
extinct Amphibia and not only is the complete skeletal anatomy 
known, but something of the soft parts, color markings, cov- 
ering and habits. Credner (10) has been able to write an 
interesting paleontological embryology based on the Branch- 
iosauria preserved in the Permian rocks of Saxony and adja- 
cent regions. The European students of the Branchiosauria 
have not, unfortunately, paid any special attention to the study 
of the lateral line system as it is preserved in the Branchio- 
sauria. Thevenin (11) barely mentions the occurrence, of the 
lateral line on the specimens he studied from the Upper Car- 
boniferous rocks of France. It is to be hoped that more may 
be added to our knowledge of this portion of the anatomy of 
the Branchiosauria. 
The form from Illinois, described elsewhere (9) as Micrer- 
peton caudatum gen. et. sp. nov. (Fig. 4), is a very small ani- 
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