in existing Species of Felidee. 327 
height and direction of this partition and in the relatively 
large size of the outer or auditory chamber; and I find 
that similar differences are observable between certain other 
species of Felidze. 
In Felis aurata, temminckii, marmorata, planiceps, viver- 
rina, nebulosa, concolor, pardalis, wiedii, and other tropical, 
or mainly tropical, species the bulla with its low partition, 
small outer chamber, and capacious inner chamber conforms, 
in a general way, to the type I have described and figured in 
Fig. 1. 
Felis pardalis. (No precise locality.) 
A. Right bulla, from below, with inner chamber laid open. 
B. The same, from inner side. 
C. The same, from outer side. 
p-, partition ; x., periotic; p.’, line of origin of partition. 
Panthera onca. In F. pardalis, for example, the groove on 
the outer side of the bulla is close to the inferior margin of 
the auditory meatus, and within the inflated inner chamber 
the partition is very low posteriorly where it passes into the 
stylomastoid ridge and increases a little in height anteriorly, 
almost the entire space of the bulla being occupied by the 
inner chamber (fig. 1). 
The opposite extreme in the structure of the bulla is 
exhibited by F. manul (fig. 2), in which the groove marking 
