REPORT ON THE NUDIBRANCHIATA. 
29 
gives off a strong branch ; the special commissures making up the united commissural 
band could not be separated from each other. The spherical olfactory ganglion is situated 
in or at the root of the rhinophore, and is somewhat smaller than the buccal ganglion. 
The buccal ganglia are of oval contour, united by a commissure, which is about equal 
to half the ganglion in diameter ; the gastro-oesophageal ganglion has a short stalk, its 
size is not more than one-sixth of that of the buccal ganglion. 
The eyes are situated on the shallow excavation of the outer edge of the cerebro-pleural 
ganglia ; the optic nerve is about as long as the diameter of the eye ; the pigment is 
black, the lens yellowish. The otolithic vesicles are situated just behind the eyes, and are 
a little smaller than them in size ; they contain some sixty otoconia of the normal 
form. 
The bulbus pharyngeus (which was half projecting) is of the typical form, 5 mm. long, 
3‘5 mm. broad, and 2‘5 mm. high ; the radula-sheath projects slightly at the hinder end 
below; the labial disk is roundish, the boundary of the spacious accessory-buccal cavities 
is clearly visible through the walls of the bulbus. The mandibles are of a clear yellow 
colour, strongly arched ; the anterior part of the upper margin is bent inwards, and forms 
a small horizontal surface, which is bounded by a keel, which, higher in front, extends 
as far as the crista connectiva ; the hinge is small ; the crista connectiva has a longi- 
tudinal furrow, which is not identical on both the jaws ; the bent masticatory process is 
short and somewhat strong ; the upper portion is quite smooth (worn out V) ; the rest was 
provided with about forty denticles, reaching, on the outer side, a height of ’06 mm. 
The denticles (PI. IX. fig. 1) are divided by an oblique slit at the top, the inner part is 
conical, more or less bent, the outer part rather wing-shaped. The tongue has a clear 
yellow radula, with six plates on the under margin and four on the shorter upper margin, 
further backwards there were thirteen developed and two undeveloped teeth ; the total 
number is therefore twenty-five. The teeth are chitinous yellow in colour, the breadth 
of the youngest (hindmost) ‘26 mm., the height *28 mm. ; these teeth (figs. 2-5) show a 
rather long slender hook and four, occasionally three (fig. 3), strong denticles of the cutting 
edge of which the one beneath is generally the smallest. 
The white salivary glands are P5 mm. long and ribband-shaped, posteriorly 
they are a little broader and lobate on the margin ; the salivary ducts are not very 
short. 
The oesophagus is short ; the stomach rather large with a short oval contour ; from 
either side two bile ducts arise from the two anterior groups of papillae, at the hinder end 
is the main bile duct; the latter opens close to the pylorus ; the inner surface is furnished 
with strong folds, which radiate out from the cardiac end. The main bile-duct is somewhat 
wider than the gut, running along the middle of the length of the dorsal surface of the 
hermaphrodite gland, receiving a bile-duct from each group of papillae commencing with 
the third, and reaching behind the hermaphrodite gland. The gut is wide, its course 
