1897.] Recent Literature. 217 
by him Gomphodontia and Cynodontia (which are, perhaps, not dis- 
tinct from each other as suborders) belong to the Theromora. They 
coincide, in all important points, differing chiefly in dentition, a character 
in which the Theromora present as many types as the Marsupialia. 
In view of these facts it became the duty of the authors of the pres- 
ent paper to retain the order Theromora, so long as others had pre- 
ceded them in reconstructing it with the advance of discovery. Also 
in discussing the phylogeny the authors should do their predecessors 
the justice to quote their latest opinions, and not their earliest, which 
they had modified or abandoned. In the paper above cited,’ and 
others, I advanced the hypothesis that the Mammalia were derived not 
from the suborder Pelycosauria, as I had at one time supposed (as 
cited by Baur and Case), but from the more comprehensive order 
Theromora, a conclusion to which they do not refer. In one paper*® I 
remark, “ The Pelycosauria could not, however, have given origin to 
the Prototheria, since in that class of mammals there is a well devel- 
oped coracoid,” etc. 
The phylogenetic inferences of the authors may be learned from the 
following quotations. After citing my opinion of 1884 that “the 
mammalia are descendents of the Pelycosauria,” they remark (p. 118) 
“Tt is quite evident that the Pelycosauria with the two temporal arches 
and the specialized neural spines cannot be the ancestors of the Mam- 
malia; they represent a specialized side branch of a line leading from 
the Proganosauria to the Rhynchocephalia, which becomes extinct in 
the Permian.” It must be remarked here that the specialized neural 
spines are not a character of the Pelycosauria, as some of the genera 
do not possess them; and I never introduced them into the diagnosis. 
The case is similar to that of the basilisks which have enormously 
elongate neural spines, yet the genus is one of the family Iguanide. It 
is, however, probable as Baur and Case remark, that the Pelycosauria 
should be excluded from the Theromora and be placed in close relation 
with the Rhynchocephalia, to which order I have already referred pro- 
visionally one of the genera (Diopeus). That the authors agree with 
me that the Mammalia are descended from the Theromora is evident 
from their conclusion that the former may have been derived from the 
suborders Gomphodontia and Cynodontia, which are Theromora. They 
say, “ These forms look very much like mammals and could possibly 
be ancestral to them.” It is thus evident that Baur’s term Sauro- 
, Mammalia, which he never defined, is a synonym of Theromora. In 
à Seienn . Amer. Philos. Soc., 1892, p. 25. Origin of the Fittest, 1887, p. 335- 
, 346, 
* Primary Factors Organ. Evolution, 1896, p. 88. 
