332 Mr. R. I. Pocock on the Auditory Bulla 
shutting off a very small outer chamber from a capacious © 
inner chamber. 
Other stages in the intergradation between these two 
types of bull are shown by F. geofroyi and F. serval. In 
I’. geoffroyi (fig. 5) the partition rises about the same distance 
below the rim of the auditory meatus as in F. chaus, and is 
only a little shallower at its deepest point than in that 
species ; but it is much shallower at its posterior end below, 
or, when the skull is inverted, above the periotie orifice 
between the chambers. From the figure, moreover, it will 
be seen that the partition lies much farther forwards within 
Felis serval, var. servalina. (Uganda.) 
A. Right bulla, from below, with inner chamber laid open. 
B. The same, from inner side. 
C. The same, from outer side. 
p-, partition ; 2., periotic ; p.', line of origin of partition. 
the cavity of the bulla than in F.. sylvestris, with which 
F. chaus agrees, and that the inner chamber is produced and 
capacious posteriorly as in /’. pardalis (compare figs. 1 and 5). 
In F. serval (fig. 6) the position of the partition within 
the bulla, and the degree of inflation of the inner chamber 
posteriorly agree with the condition seen in #’. chaus and 
F’, sylvestris ; but the partition is lower, especially behind, 
than in F. chaus, and rises close beneath the rim of the 
auditory meatus. 
Finally, in the genus Acinonyz, better known as Cynailurus, 
