534 MOODIE. [ VoL. XIX. 
far as is possible. Professor Thyng (23), in his study of 
the squamosal bone in the tetrapodous Vertebrata, reached 
the conclusion that the element usually called squamosal in 
the Stegocephala is not that element, but is the supratemporal. 
Baur had made the same statement many years previously 
when he says: “Das sogenannte ‘Squamosum’ der Stegoce- 
phalen (Huxley, Miall, Fritsch, Credner, etc.) ist aber nicht 
dieses Element, sondern in Wirklichkeit das supratemporale, 
wahrend das ‘supratemporale’ dieser Forscher das Squamo- 
sum reprasentirt’ (Baur, Anat. Anz., 1, p: 349). He aitee 
ward withdrew from this position (Anat. Anz., Bd. XI, p. 
660) and concluded that the squamosal really was that ele- 
ment. Thyng now revives this idea and bases his conclusions 
on embryological studies of several forms. His major thesis 
is not, however, well taken since he assumes it to be an ac- 
cepted fact that the quadrate of the lower vertebrates is rep- 
resented in the mammals by an element of the ear, the incus. 
This is by no means so generally accepted as he would have 
us think. His conclusions are briefly these: since the incus 
of the mammals represents the quadrate of the lower verte- 
brates and since there is an intimate relation between the 
incus and the squamosal bone in certain embryos, ergo the 
so-called squamosal of the Stegocephala is the supratemporal. 
Whatever the element lying next to the parietal may be in 
other forms, I am fairly well convinced that in the Stego- 
cephala it is the true squamosal and not the supratemporal 
(prosquamosal ). 
This position is sustained by the study of the lateral line 
canals on the crania of the extinct Amphibia and their correla- 
tion with those of the fishes. In the skull of Amia the tempo- 
ral canal, in its course forward, cuts the squamosal as it does 
in all of the Stegocephala examined where the lateral line 
canals are preserved. I take the conclusion of Allis, Pollard 
and van Wijhe that this element in the fishes is really the 
squamosal and the reader is referred to them for their reasons. 
In Polypterus according to van Wijhe, when in his dis- 
cussion of the lateral line system he says: ““Bedenkt man, dass 
