Art. XXX.—On a New Species of Chromodoris.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 18, 1885, Page 137

Art. XXX.—On a New Species of Chromodoris. By T. F. Cheeseman, F.L.S. [Read before the Auckland Institute, 1st June, 1885.] A Few months ago, Captain Farquhar, of the steamer Clansman, very kindly brought to the Auckland Museum a living specimen of an exceedingly handsome Nudibranch, found by him on the rocks at Whangaroa Harbour. Since then I have also had specimens in alcohol, of the same species, sent to me from Whangarei Heads. It proves to be undescribed, and to belong to the genus Chromodoris, of which only one species was previously known to inhabit our coasts-viz., C. aureomarginata* “Trans. N.Z. Inst.,” vol. xiii., p. 223., a pretty little animal occasionally seen in Auckland Harbour. Captain Farquhar's species is larger, and much more brightly and vividly coloured. The following is a description:— Chromodoris amæna, n. sp. Body 1 ½ to 2 inches long, linear-oblong, rounded in front, pointed behind, back slightly convex. Mantle smaller than the foot, quite smooth and even, pale pinkish or purplish lilac, with a central row of large bright orange oblong spots, and occasionally a few lateral ones, margin pale creamy or yellowish white. Dorsal tentacles (rhinophores) clavate, completely retractile within slightly raised sheaths; upper part arched backwards, laminate, laminæ from 24 to 25. Branchiæ completely retractile, 10 in number, connected at the base, small, erect, linear, simply pinnate. Both tentacles and branchiæ are a bright magenta colour. Oral tentacles free, small, conical. Foot paler than the mantle, the sides and extremity with an irregular double row of roundish bright orange spots, considerably longer than the mantle; sole, pale flesh-colour. Odontophore of about 65 rows of teeth; central tooth small, laterals from 60 to 70 on each side. Mantle spicules apparently wanting. Ova deposited in a spiral coil of four turns. Captain Farquhar's specimen lived in confinement for more than a month, during this period depositing its ova. It was lively and active in its habits, and was fond of floating in a reversed position just under the surface of the water, as is the case with many of the Nudibranchs. Its graceful form and bright colours render it one of the handsomest species yet discovered in New Zealand.