332 
at. 
at. a. 
a.v.c. 
c. s.i. 
d. e. 
d.s.u. 
J.s. 
h.c. 
p.v.c. 
s.e. 
s. 
ut. 
a.h. 
a.c. 
al.c. 
a.p. 
a.s. 
c. dv. 
cp.m 
d. p. 
ml. 
in.st. 
l.c. 
l.s. 
o.l. 
o.st. 
p- 
p.c. 
p.p. 
p)t.m. 
r.f 
r.s. 
sv.h. 
sv.k'. 
t.m. 
PROFESSORS T. W. BRIDGE AND A. C. HADDON 
IV. — The Auditory Organ. 
Atrial cavity. 
External atrial aperture. 
Anterior semi-circular canal. 
Cavum sinus imparis. 
Ductus endolympliaticus. 
Ductus sacculo-utricularis. 
Foveee sacculi. 
Horizontal semi-circular canal. 
Posterior semi-circular canal. 
Sinus endolymphaticus. 
Sacculus. 
Utriculus. 
V. — The Air-hladder. 
Air-bladder. 
Anterior chamber. 
Antero-lateral cmcum. 
Anterior pillars. 
Air sac. 
Coecal diverticulum. 
Compressor muscle. 
Ductus pneumaticus. 
Inner lateral caecum of air-bladder. 
Inner stratum of tunica externa. 
Lateral chamber. 
Longitudinal septum. 
Outer lateral caecum of air-bladder. 
Outer stratum of tunica externa. 
Pei’itoneum. 
Posterior caecum. 
Posterior pillars. 
Protractor muscle of the “ elastic-spring ” mechanism. 
Radial fibres of the tripodes. 
Fibrous ridge on the inner surface of the ventral vv^all of the anterior 
chamber. 
Sub vertebral keel. 
Projection of sub vertebral keel into the dorsal wall of the anterior 
chamber. 
Transverse membrane. 
