Report on the zoological collections made in the Indo-Pacific Ocean ...

.——62 - COLLECTIONS FROM MELANESIA.species, not mentioned by the above authors R. Jimbriata,:JR. flavescens, R. grisea, and R. plicatula. Another species whichhas also escaped attention is the Trochus melanostoma of Reeve(Proc. Zool. Soc. 1842, p. 185 ; Conch. Sjst. vol. ii. pi. 218. fig. IG).This is the same as RiseJla fimbriata of Philippi, which I thinkshould be regarded as a large form of R. melanostoma, Gmelin ;andwith this species I would also unite R. fiavescens and R. pUcatida ofPhilippi. Dunker has also described a species from Sydney underthe name of R. crassa, which appears to be remarkable on accountof a thickened channelled lip (Mai. Bliit. 1861, vol. viii. p. 42).R. Jcielmannseggl, Zelebor, is the R. lutea, Quoy, of which R.imbricata may be a variety. The two following species resembleRisella in form, but have the concentric multispiral operculumof Ti'ocJms, from which they are distinguished by their non-pearlyapertures Trochus tantillus, Gould, and Risclla isseli, Semper.The Tectarhis luteus of Gould, Risella infracostata, Issel, R. parvula,Dunker (?= tantillus), and Trochus conoidaUs of Pease willprobably have similar opercula ;these four species differ fromRisella not only in the operculum, but in being narrowly perforated.The statement with regard to Risella aurata being themale of R. nana (although both are hermaphrodite) made byMr. Tenison-Woods (Proc. Linn, Soc. N. S. Wales, vol. i. p. 244),and that " cdl breed freely with one another," seems to me to requiresome further corroboration. He himself hesitates to assertpositively that either of these two forms are incapable of reproducingtheir own kind, " for there are many places on the coastwhere no species can be found except the variety now known asR. aurata." This, in my judgment, proves that that species at allevents is self-propagating ;yet Mr. Tenison-Woods says thatspecimens of this species kept in glass jars for a few weeks did notbecome fertile. Experiments miide for so short a time are far fromconclusive, especially when made under such artificial conditions.64. Eissoina clathrata.A. Adams, Proc. Zool. Soc. 18-51, p. 265; Schwartz von Muhrenstern,Denkschrift. Akad. Wissenschaft. Wien, 1861, vol. xix. pt. 2, p. 154,pi. vi. tig. 49 ;S^nith, Journ. Linn. Soc. vol. xii. p. 553.Hab. Prince of Wales Channel, 7 fms. {Coppinger) ; PhilippineIslands {^Cuming) ; var. minor, from the Caroline Islands (J.Brazier)The specimen obtained by Dr. Coppinger is of a yellow-waxcolour, faintly tinged with rose towards the apex and at the aperture.It has the upper whorls broken off, the remaining four anda half measuring 10 miUim. in length. The figures in KUster'a'Conchylieu-Cabinet,' pi. iv. figs. 12, 13, do not give the faintestidea of this species, and probably represent another.