338 



PKOCKEDINGS OF THE MALACOLOGICAL SOCIKTV, 



branch is narrower and pinker than the ampulla, which is white. The 

 mucus gland is much diffused, semi-transparent, viscous, and hardly 

 solid. Inside it is the white albumen gland, harder and smaller (about 

 10 X 8 mm.). It is spread in ramifying tubes before it enters its 

 main duct. The spermatotheca is purplish and measures about 

 7x3 mm. ; a duct 4 mm. long leads to the spermatocyst, which 

 is whitish, pear-shaped, and about half the size. The vagina is wide, 

 with strong walls bearing ridges and lumps. 



The male branch consists of a pinkish vas deferens, about 10 mm. 

 long as it lies, but three or four times as much if stretched out. It 

 at most one millimetre wide. It passes into a sausage-shaped sack 

 about 18 mm. long and 5 broad, bent at nearly right angles. The 

 upper part is a spongy mass traversed by the narrow winding tube 

 of the vas deferens, but does not appear to be a prostate as described for 

 Anisodoris by Bergh. By a prostate I understand either a gland 

 attached to the vas deferens or a glandular swelling in its course, after 

 which it contracts again into a thin muscular portion. But in the 

 present animal the vas deferens remains constant in size, only before 

 entering the sheath of the penis (which forms the lower part of the 

 sausage- shaped sack) it passes through a spongy mass. The glans 

 penis itself is small, and no spines or other armature were found on it 

 or on the rest of the genitalia. As preserved, the genital orifices open 

 into a large striated chamber with folds or laminae on the walls, but 

 this structure may be the result of contraction and not natural. 



This form appears to have all the characters of the section Archidoris. 

 It is impossible to say whether the white excrescences are found on 

 the living animal or are an artificial deposit on these specimens, but 

 the species is characterized by its colour and peculiar texture, which 

 seem to be natural features and should render it easily recognizable. 

 It offers many resemblances to Anisodoris (Montereina) nohilis, 

 MacFarland, from Monterey, California, but the colour is not mottled, 

 the tentacles are not digitiform, and there are differences in the radula 

 and in the genitalia ; also the animal, which seems mature, is much 

 smaller, A. nobilis being as much as 20 centimetres long. 



Ctenodokis, n.subgen. 



As explained above, I regard Slaurodoris, Archidoris, etc., as sub- 

 genera or sections of Doris, L. (type Staurodoris verrucosa), and now 

 propose Ctenodoris as a new subgenus parallel to them, to include — 



1 . Ctenodoris pccten, Eliot. (See Staurodoris pecten in Eliot, 



Nudibranchiata of the Maldives, p. 557.) 



2. Ctenodoris flabellif era (Cheeseman) . 



These forms have the ordinary characteristics of the Archidorididae. 

 The back is tuberculate, the teeth simply hamate, and there is no 

 armature on the labial cuticle or genitalia. But the structure of the 

 branchial apparatus is remarkable. Not only are the plumes simply 

 pinnate as in IStmirodoris, but they are arranged in a line or crescent, 

 and the upper lip of the pocket shuts down over them like a single 

 valve. 



