316 The American Naturalist. [April, 
element. They announce the presence of a supramastoid arch whose 
elements were shown to exist in Naosaurus in the paper above cited. 
They, however, show what I did not discover, that it is separated by a 
foramen from the postorbitosquamosal arch. This foramen is either not 
‘present in Naosaurus, or it has been closed by pressure in the specimen 
I described. They describe the palatal structure better than has been 
done hitherto, which turns out to be quite similar to that which I had 
shown to exist in the contemporary Cotylosaurian genus Pariotichus. 
It is important to notice here that the supramastoid is identified with 
the bone called by Baur in the Lacertilia the squamosal. This iden- 
tification may well be questioned, since it is purely a roof bone in these 
paleozoic reptiles, while I have shown that Baur’s squamosal enters in- 
to profound articulation with the cranial walls in the Mesozoic Pytho- 
nomorpha. And it is the latter that must explain the nature of Baur’s 
“squamosal” in the Lacertilia, and not the more remote Paleozoic 
types. (See my discussion of this subject, AMERICAN NATURALIST, 
1895, 855, 1003). But whatever the relations between these elements, 
neither is the squamosal of the Mammalia, which I can now show is 
the element which I have sometimes called supratemporal and which 
Baur calls prosquamosa 
As a phylogenetic infuo ther assert that the Pelycosauria 
cannot be arranged with the Anomodontia as a suborder of an order 
of Theromora, because in the Anomodontia there is only one post- 
orbital bar. This, according to my definitions, is true, but supposing, 
that the Pelycosauria cannot be arranged with the Anomodontia on 
this ground, the statement that the Theromora “do not exist,” is not 
justified. In 1869* the reviewer revised this order, and included in it 
the Placodontia, Proganosauria, Parasuchia, Anomodontia, Pelycosau- 
ria and Cotylosauria. In 1891° it was further revised by the inclusion 
of the Proterosauride. In 1894,° following the statements of Lydek- 
ker, that the Proganosauria (founded on Stereosternum and Mesosaurus 
only) is probably a Sauropterygian type, this group was omitted, and 
the Procolophonina of Seeley was inserted, the Cotylosauria and Pseu- 
dosuchia having been already eliminated. The name Proterosauria 
(Seeley) was retained to represent the suborder for which I had used 
the name Proganosauria, minus the Mesosauride (type of Proganosau- 
ria). The order thus constituted included the Placodontia, Protero- 
sauria, Anomodontia, Theriodonta and Pelycosauria. I now add that 
it is probable that the groups discovered by Seeley in S. Africa called 
* AMERICAN NATURALIST, October. 
* Syllabus of Lectures on Vert. Paleontology, July, p. 37. 
* Proceeds. Amer. Philos. Society, p. 110. 
