ANATOMY OF THE ELEPHANT'S EAR. 
7 
surface the mastoid process rather than the mastoid -portion. 
It appears to be a sort of false mastoid portion as com- 
pared with that of man. In man the mastoid process 
is identical with the mastoid portion of the periotic bone, 
the periotic by this mastoid portion taking a part in forming 
the outer surface of the skull. In the elephant the periotic 
does not come to the surface as a mastoid process, and the 
mastoid process is an integral part of the exoccipital bone. 
From its position in relation to neighboring structures as 
well as from its shape I cannot but believe this mastoid 
process to be identical with the "paroccipital (or paramas- 
toid) process" of the exoccipital described by Flower and 
by him said to be the analogue of the jugular eminence in 
man (op. cit., pp. 98, 112, and 132) ; and yet this author 
states distinctly that in the elephant there are no parocci- 
pital processes (p. 181). In describing the skull of the 
dog, which he takes as a type for that of all mammalia, he 
speaks of the " paroccipital (or paramastoid) process" as a 
prominent process of the exoccipital serving for muscular 
attachment lying external to the occipital condyle and 
separated from it "by a deep depression," and also as 
"projecting backwards and downwards." The stylo-mas- 
toid foramen he also locates as external to this process 
(p. 119). Not only do the large pneumatic cells of 
the mastoid prominence fail to communicate across the 
suture with the far smaller cells of the deep-lying mastoid 
portion of the periotic, but they are also by the bony walls 
lying upon both sides of this same suture shut off from 
communication with the exceedingly large pneumatic cells 
surrounding the tubular auditory canal. These latter cells 
belong to the squamosal bone. The external auditory 
canal of the elephant is formed according to Hyrtl only 
by the squamous portion of the temporal bone. Flower 
describes it as formed almost exclusively .by this bone (the 
squamosal) and says that the tympanic contributes very 
