ELIOT — NUDIBEANCHS. 431 



18. Ceratosoma ornatum, Bersh. 



See Bergh, Mai. Unt. in Semper's Reisen, Heft xvii. pp. 946-7, and Eliot on C. cornigerum in Proc. 

 Zool. Soc. 1904, vol. i. pp. 401-2. 



One specimen from Seychelles, 37 fathoms. As preserved it is 37 mm. long and 11 mm. 

 broad across the back at the widest part. The colour is semi-transimrent yellowish white, 

 thickly spotted with opaque white. Round the frontal and dorsal margins and also round 

 the margin of the foot is a row of faded rose-coloured spots. The prominence behind 

 the branchiae is bordered with a continuous line of the same colour. The shape is as 

 usual. There are two wavy and not very decided lobes on either side of the mantle- 

 margin and behind the branchias a well-developed process 6 mm. long. 



I think this is the C. ornatum of Bergli, but doubt if it is more than a colour-variety 

 of C. cornigerum, Adams. 



19. Sphcerodoris levis, Bergh. 



See Bergh, Mai. Unters. in Semper's Reisen, Heft xvii. p. 924 (1890), and Eliot, in Proc. Zool. Soc. 

 1904, vol. i. pp. 403-4. 



Two specimens from Coetivy, about the same size (25 mm. long, 22 mm. broad) and 

 colour. They are brownish olive with various faint mottlings. There is a conspicuous 

 circular area round the branchial pocket, lighter and slightly depressed. In both 

 specimens there are obscure traces of dorsal ridges and two pits arranged symmetrically 

 one on each side between the branchiae and rhinophores. 



These specimens are I, think, referable to the form described by Bergh and myself 

 under the name of Sph. levis. The indications of ridges which they present suggest that 

 they may be immature and subsequently develop a more uneven and tuberculate dorsal 

 surface. It is hard to believe, however, that they are the young of Sph. punctata or 

 papillata. These two species (of which I have examined the type specimens) perhaps 

 represent different ages of the same animal, but both seem to be different from the 

 relatively smooth species. 



It is possible, but hardly demonstrable, that this animal is the Actinocyclus verrucosus 

 of Ehrenberg. 



ORODORIS. 

 This genus, recorded only from the Indo-Paciiic, comprises animals of a considerable 

 size with ridged and tuberculate backs. The large tubercles bear subsidiary knobs and 

 are irregular in shape. They are arranged so as to form a median ridge with side ridges 

 running to the mantle-margin. The branebise are tripinnate. A labial armature is 

 present. The radula is large ; there is no central tooth ; at least some of the lateral teeth 

 are finely denticulate. There is no armature on the genitalia. The affinities of the genus 

 are uncertain. In many ways it is allied to Asteronotus (especially O. striata), but the 

 buccal parts are different. Two species are known : — 



1. O. miamirana, Bergh. Philippines, Tahiti, New Britain, Zanzibar. 



2. 0. striata, Eliot. Zanzibar, Praslin. 



