1204 
SCANDINAVIAN FISHES. 
tally directed tube, utriculus (u), which dilates anteriorly 
into a vesicular bulb, recessus utriculi ( rec ), in whose 
anterior and outer sides open two vesicular tubes, the 
anterior (aa) and the external {ae) ampullce, continued 
each by a narrower, tubiform duct, the anterior ( ca ) 
and the external {ce) semicircular canals, which bend 
round and at their other end again open into the utri- 
culus, the former at the upper end of an upward in- 
vagination thereof, sinus utriculi superior {ss), the latter 
into the lower part of it. At the posterior termination 
of the utriculus, sinus utriculi posterior ( sp ), opens a 
third vesicular tube, the posterior ampulla ( ap ), which 
Fig. 362. Auditory organ of the right side: A, in a Perch ( Perea fiuviatilis ; X 3, seen from within); B, in a Sturgeon ( Acipenser sturio; 
X 37a, seen from without); C, in a Chimcera ■ (Chimcera rnonstrosa; X 3 1 / 4 , seen from within); D, in a Rough Hound ( Scylliorhwus cani- 
cula; X 3 l / 3 ), and E, in a Mud-eel ( Siren lacertina ; X 1 1 1 / 4 ), both the last seen from within. 
aa, ampulla anterior 
ае, ,. externa 
ар, ,, posterior 
ас, nervus acusticus 
ade, apertura externa ductus endolympliatici 
adp, ,, ductus perilymphatici 
ass, apex sinus superioris 
с, cutis 
ca, canalis anterior 
ce, ,, externus 
cp, ,, posterior 
cr, crista acustica ampullarum 
ers, canalis recessu-saccularis 
cus, canalis utriculo-saccularis 
cle, ductus endolymphaticus 
dep, ductus canalis posterioris 
dp, „ perilymphaticus 
l, lagena cochleae 
mn, macula acustica neglecta 
ms, ,, ,, sacculi 
mu, ,, ,, recessus utriculi 
o, otolites (in the recessus utriculi, sacculus 
and lagena) 
pi, papilla acustica lagenae 
raa, ramulus ampullae anterioris 
rae, ,, ,, externa?, 
rap, ramulus ampullae posterioris 
rl, ,, lageuae 
rn, ,, neglectus 
rs, ,, sacculi 
ru , ,, recessus utriculi 
rec, recessus utriculi 
s, sacculus 
se, saccus endolymphaticus 
sp, sinus utriculi posterior 
ss, ,, ,, superior 
sq, squamae cutis 
u, utriculus. 
