PLATE III. 
Spimla peronii. 
A vertical longitmlinal section, supposed to be taken somewhat to the left of the 
nPuUlle line. The left lobe of the liver, left posterior salivary gland, left branchia and 
half of the beaks and lips are removed ; and the section passes through the centre of the 
terminal fossa. Drawn to scale of 4 diameters. 
Oil. Wliitc (adenoid?) body. 
an. Anus. 
Au. Right auditory sac. 
C. /’. “ Ccphaloiiodiuni ” ( = head + foot). 
(/./>. Dorsal beak. 
fi.i. Median dorsal infundibular apophyse (nuchal cartilage) 
AjkS. “ E pisoma ” ( = visceral sac and mantle). 
/k Terminal fossa. 
i/.p. Brachial ganglion. 
)ip. Right lobe of the liver. 
A/xf. Duct of the right lobe of the liver. 
/. Infundibulum. 
/.e. Infundibular collar. 
Ink bag. 
in. Intestine. 
/if. Infundibular attachment. 
/.e External lip. 
/.I. Internal lip. 
/«. Lingual portion of the odontophorc. 
J/.S. “ Mesosoma ” (connecting the Cephalopodium with the Episoma). 
A/S.m. Mesosomatic muscular wall. 
oe. (Esophagus. 
o.ff. Optic ganglion. 
op. (Jptic nerve. 
/'*. P2. P*. /*. Edges of the mantle at the shell openings. 
f*®. Mantle aboral disk behind the shell, with tlie terminal fossa. 
P'. Shell-secreting surface of the mantle. 
/'’. Part of the mantle reflected over the ventral wall of the anterior chamber of the shell, 
in the middle line. 
Pyloric ceeca (“ pancreatic follicles ”)■ 
/'./. 1 )orsal and lateral lobes of the free edges of the mantle. 
Perineural cartilaginous cap.sule, cut away on the left side to show the left optic 
ganglion with the nerves proceeding from it. 
Spiral pyloric appendage or “ pyloric sac.” 
jfji/. Posterior salivary glands. 
/>fn. “ Peritoneum.” 
/\r. Ventral edge of the mantle. 
rJ. Radula. 
n/i. Hhcll. 
tpA. Sipliuncle of the shell 
fjj/K KjiP. Two last septa of the sliell. 
W. Stomach (cardiac sac). 
T. T. Tentacles (the left one is shown as it was folded in the retracted state, but the “ elbow ” 
is turned outwards and downwards). 
c./». Ventral l>eak. 
•?.«. Visceral nerve going to heart ami branchioi. 
I'oiwage connecting the right and left divisions of the viscero-pericardial cavity. 
I. II, III, IV', The inner face of the brachia of the right side. 
IV" Bose of correH]K>nding left brachium. 
p.r. 
I\>i. 
jm.c. 
