ON THE NUDIBRANCHIATA. 19 



tion. The pedal ganglia are round, the cerebro-pleural elliptical, with traces of a 

 division into two parts. 



The jaws are strong, horny, elongate, yellow, with black edges. They are 10 mm. 

 long and 4'3 wide at the broadest part. The region of the hinges is straight and flat. 

 The rest of the jaw curves outwards and is convex. The edge (fig. 7) itself is smooth, 

 but behind it are about six rows of stout denticles, which are blackish in the jaw and 

 yellowish on the short (1'5 mm.) masticatory process. Behind them are about fifteen 

 rows of flatter, roundish prominences, not amounting to denticles. The radula is of the 

 type usual in Tritonia, with a formula of 29 x about 50.1.1.1.50. The median (fig. 8) 

 tooth is tricuspid, the central cusp, pointed, those at the side blunt. The first lateral 

 (fig. 9) is of the usual clumsy shape; the rest (fig. 10) are hamate, moderately stout 



FIG. 9. 1st lateral. FIG. 10. Laterals. 



FIGS. 9 and 10. Tritonia appendiculata. 



and moderately curved. The tips are often broken off, particularly near the middle of 

 the radula. 



The salivary glands are 8 mm. long, thin, ribbon-shaped above, slightly flocculent 

 below. The oesophagus is at first narrow, but rapidly broadens out and enters the thin 

 membranous stomach. About half of the stomach is surrounded by the brownish- 

 yellow liver, which is itself surrounded by the hermaphrodite gland. The intestine 

 leaves the stomach at the point where it emerges from this covering of liver and gland. 

 It is strong and thick, and turns to the right after a slight bend forwards. Both the 

 stomach and the intestine were filled with blackish matter, with which were mixed some 

 bright red spiculous animal fragments. 



The hermaphrodite gland consists of bright pale-yellow bodies set in colourless jelly. 

 The mucous and albumen glands are large, both greyish-yellow. The spermatotheca is 

 elongate, with a short duct. The vas deferens is convoluted. The verge is broadly 

 conical at the base, with a thin pointed top. 



This species offers many points of resemblance to T. challengeriana (Bergh, 



(ROY. soc. BDIN. TRANS., VOL. XLI., 527.) 3 



