OCR Text |
Show 1 9 0 6 . ] OF SOUTHERN INDIA AND CEYLON. 66 9 monstrosity, and can bear the name Thimna, as suggested by Bergh. About thirteen species of Nembrotha are fairly well characterised. The dentition of N. rubro-ocellata B. (Siboga, pp. 201- 2) is unknown, and it does not seem to me that the animal is sufficiently distinguished externally from other forms such as JV. rubropapidosa:- f 1. iV. nigerrima B. J ' (See Eliot, Proc. Zool. Soc. 1904, ii. p. 90, ' and Bergh, Siboga, 1905, p. 195.) 3. N. kubaryana B. ^ 4. N. coerulea Eliot. 5. N. lineolcda B. f 6. -ZV. amitina B. \ 7. N. morosa B. f 8. N. diaphana B. ■ 9. JV. gratiosa B. 1 10. N. qffinis Eliot. [ 11. A. verconis Hedley & Basedow. (Trans. Roy. Soc. S. Austr. 1905, vol. xxix. p 158.) f 12. N. gracilis B. \ 13. N. rubropapidosa B. The brackets merely mean that the species are allied, and do not necessarily imply probable identity. It is possible, however, that some of the species are only colour varieties. Nos. 1 to 4 are dark, with a comparatively wide radula containing about 12 teeth on each side of the rhachis. N. lineolata is yellowish with fine brown lines and 8 teeth on either side of the rhachis. In the remaining species the radula is narrow and there are only 3 or 4 teeth on either side. Nos. 6 and 7 are dark; nos. 8 and 9 present a brilliant combination of colours in which bright yellow and dark blue are prominent. N. gracilis and N. rubropapidosa both have a tricuspid rhachidian tooth and a similar coloration of black and red. T r e v e l y a n a c eylonica Kelaart. (Kelaart, Ann. & Mag. Nat. Hist. April 1858, vol. i. no. 4, p. 257, and pi. x. B. Eliot, Proc. Zool. Soc. 1904, ii. pp. 86-7. Cf. Trev. rubromaculata Bergh, Siboga, pp. 189-191.) There can be but little doubt that Bergh's T. rubromaculata is the same as the earlier T. ceylonica, for the agreement in characters, both external and internal, is almost complete. The radula in Bergh's specimen seems to have been somewhat larger than in mine (from East Africa), though it is not quite clear whether there were 16 or 32 teeth on each side of the rhachis. The species can be recognised externally by the colour and by |