of the Carnivora Fissipedia. 113 
form and structure of the auditory bulla. Although the 
degree and form of inflation are characteristic of various 
groups of Carnivora, they cannot be used in a systematic 
sense, beeause, like all characters of proportion merely, there 
is no way of expressing them in a tangible form. For if the 
forms in question pass into each other, the gradations are 
insensible, and not sensible, as is the case with an organ com- 
posed of distinct parts. The same objection does not apply 
so much to the arrangement of the septa of the bulla. The 
septum is absent in the Arctoidea of Flower (Urside of 
Turner), small in the Cynoidea, Flower (Canide, Turner), 
and generally large in the A‘luroidea, Flower (Felidx, Tur- 
ner). But here occurs the serious discrepancy that in the 
Hyeenide, otherwise so nearly allied to the Felide, the sep- 
tum of the bulla is wanting. Nevertheless the serial arrange- 
ment of the order indicated by Flower, viz. commencing with 
the Arctoidea, following with the Cynoidea, and ending with 
the A‘luroidea, is generally sustained by the structure of the 
auditory bulla and by the characters of the feet and dentition, 
as well as of the cranial foramina. ‘Turner’s arrangement in 
the order, Urside, Felide, and Canide, is not sustained by 
his own characters; and its only support is derived from 
Flower’s observations on the external or sylvian convolution 
of the hemisphere of the brain*. There are three simple 
longitudinal convolutions in the raccoons; in the civets and 
cats the inferior convolution is fissured at the extremities, 
while in the dogs it is entirely divided, so that there are four 
longitudinal convolutions between the sylvian and median 
fissures. 
An important set of characters hitherto overlooked confirms 
Flower’s order. I refer to those derived from the turbinal 
bones. In the ursine and canine forms generally the maxillo- 
turbinal is largely developed, and excludes the two ethmotur- 
binals from the anterior narial opening. In the Feline group, 
as arranged by ‘Turner, the inferior ethmoturbinal is developed 
at the expense of the maxilloturbinal, and occupies a part of 
the anterior narial opening. These modifications are not, so 
far as my experience has gone, subject to the exceptions seen 
in the development of the otic septa and molar teeth, while 
they coincide with their indications. The seals possess the 
character of the inferior group, or Urside, in a high degree. 
The characters derived from the paroccipital process are of 
limited application, as the study of the extinct forms shows. 
I would then divide the fisstped Carnivora into two tribes, 
as follows :— 
* Proc. Zool. Soc. Lond. 1869, p. 482. 
Ls 
