420 PEKCY SLADEN TEUST EXPEDITION. 



7. Sclerodoris osseosa (Kelaart). 

 See Alder & Hancock, in Proc. Zool. Soc. 1864, p. 121 ; Eliot, in Proc. Zool. Soc. 1903, vol. ii. 

 p. 380, and Eliot, in Journal of Linnean Soc, Zoology, vol. xxxi. 1908, p. 113, on Peronodoris 

 and its allies. 



One small specimeii from Coetivy. 



Shape nearly circular. Length 12 mm., breadth 10. The whole surface of the 

 back, both the ridges and the depressions between them, is covered with minute 

 granulations. The feet and underside are pale yellow. The ground-colour of the back 

 is purplish and produced by a multitude of little dots, but the ridges are yellowish. 

 They consist of one principal ridge running from the rhinophores to the branchiae and 

 numerous irregular side ridges, which are connected here and there, and often form 

 bumps at the point of junction. The rhinophore-sheaths are raised but closed. The 

 branchial pocket is also closed, but seems to be toothed. On the ridge in front of it is a 

 large flat piirplish depression. The integuments are crammed with short spicules, 

 straight or bent and often granulate. The oral tentacles are moderately long and 

 distinct. The anterior margin of the foot is grooved. It is not clear if the upper 

 lamina is notched or not. 



There is no labial armature. The formula of the radula is 36 x about 45 . . 45. 

 The teeth are simply hamate, the outermost are a little irregular. 



No spine or other armature was found on the genitalia, but its absence cannot be 

 regarded as certain. 



8. Peltodoris mauritiana, Bergh. 

 Bergh, Mai. Unters. in Samper's Reisen, Heft xvi. 2, pp. 815-7. 



Three specimens, labelled " Salomon." They are all much distorted and rolled up 

 into balls. The length is about 40 mm. and the breadth about 25 mm. Two of them 

 are pure white, but seem to have faint spots under the skin. The third is mottled with 

 pale purplish grey. The dorsal surface is much puckered in all specimens, but 

 apparently the ridges which it now bears are not natural. The rhinophore-sheaths are 

 entirely closed and appear as low mounds. The branchiae are six in number and 

 tripinnate; the branchial pocket is six-toothed. The hard, rough dorsal surface is 

 covered with small spiculous papillae set not very close together. The dorsal integu- 

 ments are crammed with short spicules, either straight or bent. The wide mantle- 

 margin measures 8-9 mm. The foot isvshort and narrow. 



There is no labial armature. 



The formulse of two radulas examined are : (a) 21 X 35 . . 35 and (6) 28 X 40 . . 40. 

 The teeth are simply hamate. Those in the middle of the half-rows are large. The six 

 or eight nearest to the rhachis on either side are smaller, witli long bases which bear a 

 projection or denticle. The innermost often cross over the rhachis. The outermost are 

 smaller but not degraded. The genitalia are small and undeveloped ; the orifices 

 are invisible externally and no armature was found. 



