REPORT ON THE NTTDIBR AN CHIATA. 
123 
“ islands,” with the exception of the caudal veil ; here and there are small, whitish, 
knob-like elevations, not exceeding 1 mm. in diameter. The club of the rhinophoria 
has on either side about thirty leaves and a strongly developed terminal papilla. The 
branchial cleft is transversely oval ; the strongly retracted brancliia is formed of 
eight tripinnate branchial leaves; the branchial circle is completed by the anal 
papilla (about 2'5 mm. high), whose opening is slightly prolonged downwards on the 
anterior side ; at its base, a little to the right, is the renal aperture. The mouth is 
a fine pore, on either side of which is an inconspicuous knob-like tentacle. The foot 
is as usual. 
The position of the intestines is as usual ; the peritoneum is colourless. 
The central nervous system is enclosed in the usual capsule, which is as usual attached 
by frenula to the region above and between the salivary glands. 1 The clear whitish- 
yellow ganglia form a thick ring, the upper half of which in the middle line is about 
double as long (from before backwards) as the lower half. The arched upper half of the 
ring appears beneath the lens to be very granular, the granules measuring about '5 mm ; 
it is broader behind, with a superficial median longitudinal furrow marking the boundary 
between the two halves ; the under surface is smooth ; the lateral portions pass into the 
smaller under half of the ring, which lies forwards ; they are separated from it by a slight 
groove. The cerebral ganglia are long and larger than the pleural, which are situated out- 
side their hinder part. From the cerebral ganglia arise the nervi orales ; in front is 
the short-stalked ganglion olfactorium proximale, giving off the long winding nervus 
olfactorius, which at the base of the rhinophorion swells into a small round ganglion olfac- 
torium distale, which gives off two nerves upwards ; on its outer side is the short nervus 
opticus. The pleural ganglia give off the nervi palliales anteriores and the nervus palli- 
alis longus ; behind on the right ganglion, close to the pedal ganglion, I found another 
small ganglion (genitale 1). The pedal ganglia are about as large as the pleural, they 
are plano-convex, thicker in front, where they are obliquely sloped ; they are united 
by a short, broad, thin commissure (behind which is a narrower double commissure, com- 
posed of the sub-cerebral and pleural commissures) ; the ganglia give off three pedal 
nerves. The buccal ganglia are about as large as the proximal olfactory ganglia, and 
lie between, and a little in front of, the salivary glands, in contact with each other ; at 
their outer part is a somewhat disconnected portion, which may represent gastro- 
cesophageal ganglia. 2 
The eyes are provided with black pigment and a yellow lens ; the optic nerves are a 
little longer than the eyes, taking their origin from small optic ganglia a little larger than 
the eyes. The otocysts are a trifle larger than the eyes, containing a quantity of otoconia 
1 Loc. cit., 1880, p. 301. 
' L I have also seen a similar appearance in Doriopsis atropos, Doriopsis krebsii, and Doriopsis tristis. 
