1895.] Geology and Paleontology. 1003 
Reply to Dr. Baur’s critique on my paper on the Parocci- 
pital bone of the Scaled Reptiles and the Systematic Posi- 
tion of the Pythonomorpha.—In the following pages I continue 
the discussion of the questions raised by Dr. Baur in his papers. 
I. THe PAROCCIPITAL OF THE SQUAMATA. 
Dr. Baur in the paper just preceding reiterates the opinion that the 
parotic process of the exoccipital bone of the scaled reptiles includes 
the paroccipital element, and that I have fallen into a serious error in 
supposing that his squamosal isthe true paroccipital. He cites various 
authorities against me and intimates that I am not familiar with the 
literature, which he says is accessible. In this last statement he is un- 
doubtedly correct, as the greater part of it is in my private library. 
I must call my eritic’s attention at the cutset to the fact that my last 
paper has reference to the elements which support the quadrate bone, 
and not to the presence or absence of the opisthotic element of Huxley. 
It was not necessary, therefore, to enter into an exposition of the evi- 
dence for the existence of the latter which, as he says, has been proven 
by Siebenrock and Leydig in the lizards, Rathke in the snakes, and 
himself and Siebenrock in the Rhynchocephalia. It is the element 
which supports the quadrate bone for which the name paroccipital 
(Owen) is appropriate, while the element which includes the posterior 
semicircular canal is the opisthotic of Huxley. 
Baur asserts that the so-called parotic process of the exoccipital 
which supports the quadrate in the Squamata is the same element as 
that termed opisthotic by Huxley. This I deny, and believe that in 
this it is Baur and not myself who has fallen into error. Siebenrock 
instead of asserting this to be the case, denies it in the following lan- 
guage:° “ It is not the processus paroticus of the pleuroccipital (exoc- 
cipital) which is homologous with the (paroccipital Owen) opisthotic 
Huxley, but the portion anterior to the foramen nervi-hypoglossi 
superius which protects the organ of hearing.” Siebenrock here uses 
the names of Owen and Huxley as referring to the same element, but 
he makes the clear distinction, which is the important point, between 
the parotic process of the exoccipital and the element which contains 
the posterior semicircular canal. What then is the element which 
articulates with the quadrate in the different orders of the Reptilia ? 
In the Testudinata, and, according to Baur, in Sphenodon,” the 
®Sitzungsber. Wiener Akademie, 1894, p. 285; On the Skeleton of Lacerta 
simonyi. 
10 Siebenrock, Sitzungsberichte Wiener Akad. Wiss , 1893, p. 254. 
