REPORT ON THE NUDIBRANCHIATA. 
107 
club of the rhinopliore was of a greyish-chocolate colour, and the gill-leaves showed a 
similar colouring. — The animal was of a softish consistency. 
The form of the body was a longish-oval, somewhat flattened ; the dorsal surface quite 
even; the mantle edge projecting about l-3‘5 mm., and most strongly developed behind. 
The rhinophorial cleft oval, with a slightly prominent margin ; the stem of the rhinopliore 
is strong and somewhat compressed ; the strong club, bent backwards, is about as long as 
the stalk, its upper side is somewhat flattened, the under somewhat keel-shaped, the 
number of leaves on each side is about twenty -five. The branchial cleft is transversely 
oval (of about 2 '5 mm. diameter), with a slightly prominent reversed margin; the 
branchia is formed of five tripinnate leaves, of which the two hindermost are very deeply 
cleft, so that there appear to be seven divisions. Behind the branchial arch, and com- 
pleting it, is the somewhat cup-shaped anal papilla, which has a crenate margin ; at its 
base in front is the fine renal pore. The wrinkled genital papilla occupies its usual 
position. On either side of the stellate mouth-aperture is a strong knob-like tentacle, 
with a longitudinal furrow on the outside which is deeper at the end. The foot is 
rounded anteriorly and posteriorly, and does not stand out much from the sides of the 
body ; on its anterior margin is a fine furrow. 
The intestines are hardly visible from the exterior. The peritoneum is colourless. 
The central nervous system is strongly flattened. The cerebro- pleural ganglia are 
longish ; the line dividing the two parts is very distinct, especially on the outer margin ; the 
pedal ganglia are larger than the pleural, and lie outside the middle part of the cerebro- 
pleural ; they are of a short oval form and are almost divided into two parts. The 
common commissure composed of the three ordinary divisions ; at the base of the 
hindermost (pleural) is a small ganglion genitale. The sessile bulb-shaped proximal 
olfactory ganglia are united with the equally sized distal by a winding nerve. The 
buccal ganglia are roundish, and about the same size as the last, united by a commissure 
so short as hardly to merit the name ; a small swelling on the nervus gastro- 
cesophagealis represents its ganglion. 
The eyes are nearly sessile, with black pigment and a yellow lens. The otocysts, visible 
under a lens as small chalk-white bodies, are about as large as the eyes, and are filled with 
a mass of brownish-yellow otoconia, each about '02 mm. long (mostly possessing what 
appeared to be a nucleus). The broad, rather thin lamellae of the rhinophores have no 
spicules. The skin of the back has no large spicules and but few hardened cells, which 
were also nearly absent in the interstitial connective tissue. 
The buccal tube is strong, 3 mm. long, and has the ordinary three pairs of retractor 
muscles; its interior is as usual. The bulbus pharyngeus is strong, 3 mm. long by 2 '5 mm. 
broad and 2’6 mm. high ; the radula-sheath projects downwards about ‘4 mm. ; the strong 
retractor muscles are as usual. The labial disk has a covering of a thick white cuticle 
without any trace of armature ; the mouth opening is four-rayed. The tongue is broad, 
