170 
ON THE ORGAN OF HEARING, &C. 
D, Part of the cavity of the vestibules, formerly occupied by 
the reticulated membranous substance. 
E, The auditory nerve ; part of the meatus intern us cut away. 
F, The anterior and posterior cartilaginous semicircular canals. 
G, The membranous horizontal canal. 
The ampulla of the anterior membranous canal. 
I, The fossa angorse, containing the cornu angorse and ango- 
rian appendage of the great sac. 
The parts appear more elevated than in their natural position, 
in order to comprehend as extensive a view as possible. 
PLATE 11. 
Fig. 1. A view of the spherical plexus of the Squalus canini — 
four times the natural size. 
A, The spherical branch of the auditory nerve. 
B, The plexus embracing the inner and posterior parts of 
the spherical sac. 
C, The termination of the short filaments of the spherical 
branch seen through the sac. 
D, The united filaments making a kind of half-turn, and 
perforating the ampulla of the horizontal canal. 
Fig. 2. View of the distribution of the branches forming the sabu- 
lous plexus — four times the natural size. 
A, The sabulous nerve^, the branches of which form the 
plexus. Sometimes the nerve is awanting; in 
these instances the posterior nerve gives off bran- 
ches to form the plexus. 
B, The nervus communicans. 
C, The fossa angorae, the dark shaded pai'ts below the 
communicating nerve is the depression covered by 
the membrane that lines the vestibule. 
D, The horizontal canal. 
Fig. 3. The appearance of a portion of the Sabulous Body of the 
Squalus canini, as seen through the compound micro- 
scope—parts coloured agreeable to nature. 
