340 I'KOCEEDINGS OF THK M ALACOLOGICAL SOCIKTY. 



Through the kindness of Mr. E. A. Smith I have been allowed to 

 examine the type-specimen of this form preserved in the British 

 Museum. 



The external features are as described by Abraham, and the length 

 is about 13 mm. The colour is greyish, with an indistinct brownish 

 longitudinal band extending from the rhinophores to the branchiae, 

 and bordered on either side by a bluish band, the colour being due to 

 pigment disposed between the dorsal tubercles in a reticulate pattern, 

 but not on them. These tubercles are minute, cylindrical, twice as 

 long as they are broad, and ci'ammed with straight granulated spicules, 

 which are often swollen in the middle. The borders of both the 

 rhinophorial and branchial pockets are flattened, but appear to have 

 been raised in life and to have borne small pointed tubercles. The 

 branchise are small and retracted. They appear to be 9, and simply 

 pinnate or bipinuate. The oral tentacles are distinct, linear, and 

 rather flat. The foot is grooved in front and the upper lamina 

 notched. 



In the central nervous system the eyes are large and distinct. The 

 ganglia are granulated and fused into one mass, in which no division 

 is visible, though three lateral projections seem to indicate the 

 cerebral, pleural, and pedal portions. 



Small granules or columns were found in the labial cuticle, but 

 they are not arranged in a plate. The formula of the radula is 

 69 X about 82 . . 82. The innermost lateral (Fig. Sa) is hamate, and 

 bears on the inside numerous (30 or more) fine, comb-like denticles. 

 The second to the eighth laterals (Fig. 3b) are also hamate ; the shaft 

 is slender and pointed, the base stout with a large projection. These 

 teeth gradually pass into the third form, which prevails from 9 to 36 

 (Fig. 3(?). The shaft gradually grows longer and the base smaller, 

 until the whole tooth has the shape of a hook on a pedestal. In the 

 remaining 45 teeth (Fig. 3d) the base is still smaller, the shaft is 

 longer, and the end is split into 2-4 long denticles, forming a brush 

 at the tip. These teeth resemble filaments rather than the ordinary 

 teeth of Dorids. As preserved they lie in bundles on the top of the 

 other teeth, being apparently set higher up on the sides of the 

 buccal cavity. Their bases are so close together that they seem to be 

 fused, but this is not really the case : each tooth is separately 

 attached to the basal membrane. The genitalia seem small and 

 immature. No armature was found. The hermaphrodite gland is 

 spread over the anterior part of the liver only, and was not visible in 

 sections of the posterior part. 



The dentition of this species is remarkable, but appears to be 

 much the same as that of Rostanga pulchra, MacFarland, from 

 California. Cheeseman's Doris ruhicunda seems also to be a Rostanga, 

 and is perhaps identical with this species, in which case Abraham's 

 name has priority. The present specimen does not look as if it had 

 ever been scarlet, but Cheeseman's statement that D. ruhicunda has 

 sometimes a darker line down the centre of the back makes the 

 identification probable, though it is curious that he does not describe 

 the remarkable features of the radula more fully. MacFarland states 



