Art. XXIX.—Note and Description of a possibly new Species of Aplysia.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 12, 1879, Page 270

Art. XXIX.—Note and Description of a possibly new Species of Aplysia. By F. H. Meinertzhagen. [Read before the Hawke's Bay Philosophical Institute, 17th May, 1879.] Animal a dark brown (kelp colour), spotted all over with grey pepper coloured spots. The edges of the lower lobe of the mantle marked evenly with alternate darker brown and grey. The lobe covering the shell striped with grey, all of which stripes point to, and narrow towards, the apex of the shell. Posterior sides of upper tentacles also a peppery grey colour. Shell faintly but finely striated concentrically, horny and flexible at the edges. Length of shell 1·15 inches, breadth 0·65 inches. Length of animal about 5 inches. Habitat: Waimarama, Hawke's Bay. The above animal appears to me to differ in colouring from A. brunnea, described by Capt. F. W. Hutton.‡ Trans. N.Z. Inst., Vol. VII., p. 279. The shell also appears to me to differ in its measurements from those given by Capt. Hutton, and in appearance from that figured in his plate, being much longer in comparison with its breadth.

The coarse striations and shape of the shell of A. venosa leave no doubt that my specimens differ from that animal. All my specimens discharged the purple fluid (which is characteristic of the genus) on being placed in fresh water, or otherwise annoyed. I noticed also that the lower lobes, which some authors say are used in swimming by this genus, are only used in that way by this species in a very qualified sense. They attach themselves to a rock or to sea-weed by their tail, and allow their body to drift about, simply guiding the direction of their body, and maintaining their upright position, by the movement of the lobes. As in Parmophorus, Bulla and Haliotis the shells of younger individuals were much larger in relation to their bodies than those of mature age. The two species, A. brunnea and A. venosa, are, as far as I am aware, the only species of this family recorded in New Zealand; Capt. Hutton, in his “List of the Marine Mollusca of New Zealand,” mentions a single shell from the Bay of Islands. The habitats given for his two species are Wellington and Dunedin. The occurrence of this Mollusc in this Province is therefore worth recording, even if it should prove to belong to one of those two species. If as I think, it is new, it requires to be put on record. I have, however, not had the advantage of seeing specimens of either of the above-mentioned species, so that I cannot definitely state the fact that it is new. Should it be so, I suggest that it should receive the name Aplysia tryonii, as a gentleman of the name of Tryon discovered it here, where I have (I trust not unobservantly in matters connected with conchology) lived for 11 years without having observed it.