20. Galaxaria cylindrica, Lamouroux. Corallina cylindrica, Soland. and Ellis, 114. Icon. Soland. and Ellis, t. 22. f. 4. 21. Spongia muricina (?) Lam. Hist. 2 369. Number 74. Icon. Seba. Mus. 3 t. 97. f. 2. 22. Spongia perfoliata, Lam. Hist. 2 370. Number 78. Icon. -- 23. Spongia basta, Pallas. Zooph. 379. Lam. Hist. 2 371. Number 82. Icon. -- Esper. 2 t. 25. 24. Spongia alcicornis, Esper. Lam. Hist. 2 380. Number l26. Icon. -- Esper. 2 page 248. t. 28. 25. Spongia spiculifera ? Lam. Hist. 2 376. Number 106. Icon. -- Three or four other species of Spongia were brought home, which I have not been able to identify with all of Lamarck's descriptions, or with any figures; but as this author has described many species from the collection of Peron and Lesueur, which have not hitherto been figured, I have not considered them as new, until I have had an opportunity of examining more New Holland species, and of seeing those described by Lamarck. ... MOLLUSCA. BY JOHN EDWARD GRAY, ESQUIRE, F.G.S. 1. CONCHOPHORA. 1. Solenomya australis. Solemya Australis, Lam. Hist. 5 489. Mya marginipectinata, Peron and Lesueur. 2. Mactra abbreviata ? Lam. Hist. 5 477. n. 20. Icon. -- This collection contains a considerable number of specimens of a shell agreeing with the short specific character given by Lamarck of the above; but as it has not been figured, I have referred to it with a mark of doubt. The shells are rather solid, white, or white variegated with purple, with numerous concentric wrinkles, which are more distinct nearer the margin; the umbones, covered with a thin pale periostraca, nearly smooth and polished, with a small purple spot, the inside white, with the disk and posterior slope purple; the anterior and posterior slopes distinct, the lunule and escutcheon deeply and distinctly sulcated; length fourteen-tenths of an inch; height one inch. 3. Mactra ovalina, Lam. Hist. 5 477. This shell is nearly of the same shape as the last, but the anterior slope is rounded and circumscribed, and the posterior only marked by a raised line in the periostraca. The shell is thin, white; with a pale brown and deeply grooved escutcheon. 4. Solen truncatus, Wood. Conch. Solen ceylonensis, Leach, Zool. Misc. 1 22. table 7. Solen vagina, b. Lam. Hist. 5 451. Icon. Wood. Conch. t. 26. f. 3. 4. Ency. Method. t. 222. f. 1. 5. Cardium tenuicostatum, Lam. Hist. 6 5. Icon. -- The shell when perfect is white, with rose-coloured umbones; the rose colour is often extended down the centre of the shell, forming concentric zones. 6. Lucina divaricata, Lam. Hist. 5 541. Tellina divaricata, Gmel. Sys. Nat. 1 3241. Icon. Chemn. Conch. 6 134. t. 13. f. 129. 7. Venerupis galactites, nob. Venus galactites, Lam. Hist. 5 599. Icon. -- The fact of Lamarck having placed in the genus Venus this shell, which a modern conchologist has considered as a variety of Venerupis perforans, shows the very great affinity that exists between those genera.