PLATE VI. 
Spirula 
Fi^. 1.— The j^Teater part of the alimentary canal, dorsal aspect ; x 4. 
Fij{. 2.— Ventral aspect of fig. 1, the liver removed. 
Fig. 3. — The posterior juirt of the oesophagus, the stomach and commencement of the intestine ; the dorsal wall 
removed and also the e.\tremity of the pyloric sac ; seen from within. 
Fig. 4. — The pyloric sac seen from within. 
Fig. ft. — The tennination of the intestine with the small ink bag. 
In all these figures : 
a. Fold of the anterior face of the pyloric appendage. 
ca. Cardia. 
cr. Canliac portion of the stomach. 
rr'. C;ead diverticulum of cr. 
gl. Gastric ganglion. 
hd. Hepatic duct. 
li. Liver. 
ov. Ova. 
pc. “ Pancreatic ” ca'ca. 
p$. Pyloric sac of the stomach. 
pttu “ Peritoneal ” sac. 
py. Pylorus {h\j in the fig.). 
pyl. Pyloric valve, 
r. Rectum. 
z. Apparently glandular body in the fold of the “ peritoneum.” — Other letters as before. 
Fig. 6. — Me<lian longitudinal section of the buccal mass, left side. 
dh. Dorsal beak. rd. Radula. 
li. Internal lip. s.d. Salivary duct. 
In. “ Tongue.” 
Fig. 7. — Enlarged \-iew of fig. 6, from the right side. — Letters as before. 
Fig. 8. — Heart and neighbouring organs, in itilu, dorsal aspect. 
ao.a. no. n. Anterior and posterior aorta, 
rtwr. aur. Right and left auricles. 
hr.h. br.h'. Right and left branchial hearts. 
hr.app. Branchial heart appendage (pericardial gland). 
pl.v. Pallial vein, 
r. Ventricle, 
r.r. Alxlominal vein. 
X, x'. Right and left kidneys. — Other letters as before. 
Figs. !J and 10. — Aeetabula, ventral and lateral aspects, x 100. 
h. The horny lining. pa. Central papilla. pd. Peduncle. 
Fig. II. — The olfactory papilla. 
F*ig. 12. — The right eye from above. 
c. Concentric circles of the iris. m. Muscles. p>p. Pupilary aperture. 
Fig. 13. — External (lateral) view of the right eye. 
a. Optic nerve (between the removed optic ganglion and the eye). 
an. PaljKibral or corneal aperture. 
gl. Fatty gland. 
oc. Walls of the ocular chamber. 
jm.e. Perineural cartilage. 
•c.lig. Sclerotic ligament. 
Fig. 14 - A sagittal median section through the pallium of the ixisterior end of the body. 
a. I’apilla. 
h. E«rge8 of the fossa. 
ehr. Chromatophores. 
ep. Epidermis. 
/. I^-nticular mass of fibrous tissue, 
m. Ixiyer of glassy-looking sulistance. 
r. Ixiyer of fibres proceeding from the centre to the circumference r'. 
*p. SjKinge spicule. 
». Point of tlic section, fig. 17. 
Fig 15 EnUrgwl view of a j»art of fig. 14. — Letters as before ; at y the parts are obviously tom and otherwise 
injured. 
F g. 1« Part «<f the lenticular Ixxly (/, fig. 14) much enlarged. 
n. N uclei cmlieddea among the fibres. 
Pig 17. 1/ 'ngitudinal antero-posterior section of the mantle. 
K. Outer side. 7. Inner face. 
