and description of each. I am really very much indebted to Dr Fleming for his kind assistance, and sincerely wish I could in conscience support his Cydonium to the exclusion. of Geodia. Present my respects to him." In February 1856, Dr Bowerbank says, "I have just received such a glorious box of sponges from Western Australia, radiant with colour, purple, rose, cream, and all sorts of tints, and full of fleshy matter. There are forty-four grand specimens, some eighteen inches high, but when shall I get to work on them! I am overwhelmed with material, having received advice of another large collection of sponges and corals from Madeira, which are on their way. I think I must take Finsbury Square by-and-by, or I shall have no chance of exhibiting them. I am glad you and I agree so well regarding the arrangement of the Spongiada. It is quite delightful to have some one like yourself to write to about them, all the rest of the world seem to dread them as much as they do human sponges. I am working nightly for four or five hours at them, but seem to make slow progress; but the labour is most delightful to me, and every day brings some new fact before my eyes. I have now named and ready for drawing above a hundred different forms of spicula, and I am working hard to get them ready for a paper for the Royal Society, if possible, this season. In the spring I shall go to Tenby, and have two or three weeks' work at the living specimens, and work out all my suspicions and beliefs regarding them." The result of this visit to Tenby was stated in a paper read at a meeting of the British Association in 1856, "On the Vital Powers of the Spongiada," in which Dr Bowerbanks proved by observations made on Hymeniacidon caruncula, that this sponge possessed the power of expanding and contracting the oscula at pleasure while in a living condition, but he could not at that time satisfactorily determine the nature and powers of the imbibing pores, as these organs could only be seen distinctly in operation in very young and transparent specimens. These observations were followed up by others on the fresh-water sponge, Spongilla fluviatilis ; and in another communication at a meeting of the British Association held in 1857, it was proved that the organs of incurrent action were situated within the large intermarginal cavities, as in Grantia ciliata, and not immediately around or within the pores. The vigorous imbibition and ejection of the surrounding water was as strikingly indicative in the fresh-water sponge, as it was in the marine one, of the period of feeding; while the languid action in either case distinctly marked the ærating process only, during which the digestion of the nutritive particles previously imbibed is gradually effected, and the effete matter partially ejected. "The structure of the pores, and the perfectly plastic nature of the dermal membrane, as exhibited in these observations," Dr Bowerbank says, "are very remarkable. The sensitiveness of the sponge to injury, the rapidity of the act of closing those organs, and the power they appear to possess of opening new ones to any extent, and in any direction they please, attest an astonishing amount of vital energy in a membrane in which he had been unable to trace any indication of the existence of fibrous tissue." On the 18th of June 1857, a paper was read before the Royal Society of London, "On the Anatomy and Physiology of the Spongiada." By J. S. Bowerbank, LL.D., F.R.S., &c. In that highly valuable and original monograph, Dr. Bowerbank points out the faulty system of Lamarck, founded upon external form, "inasmuch," he says, " as there is no class of animals in which the form varies to so great an extent, according to the difference of locality, or other circumstances." He remarks "that the division of the Spongiado by their chemical constituents, adopted by Fleming, Grant, Johnston, and other modern naturalists, may serve very well to separate them into primary groups, but that these are far too limited to be applied as generic characters." He therefore rejects both systems, retaining the latter for forming primary divisions only, and proposes founding the generic characters principally on the organic structure and mode of arrangement of the skeleton. Dr Bowerbank accepts all the well-established genera of his predecessors, such as Tethea, Geodia, Dysidea, but confines each genus strictly within the bounds indicated by the peculiar mode of the structure of the skeleton which exists in that species of sponge which is the oldest established and best known type of the genus, and refers all others that may distinctly differ from that type to new genera founded on structural principles. When Dr Bowerbank commenced, in like manner, a critical examination of the specific characters of preceding authors, and endeavoured to collect and classify them, he found them to be still more indeterminate than those of class or genera; it appeared to him that there was scarcely an approach to a distinct terminology of the science, and that the same author frequently designated the same organ, under different circumstances, by a totally different name. He therefore felt it absolutely necessary, before proceeding to the description of new species, to enter into a thorough systematic examination of the organisation of the whole of the species within his reach, and to characterise the organs in such a manner as to render the terms he applied to them definite in their meaning, and limited in their application; and in pursuing that object he quickly found abundance of constant and well characterised forms and combinations of organisation capable of being applied with precision to the purposes of generic and specific descriptions.” He therefore proposes to characterise the elementary tissues in the following order : 1. Spicula, 4. Fibrous tissues, 2. Keratode, or horny substance, 5. Cellular tissues, 3. Membranous tissues, 6. Sarcode; And to treat of the organisation and physiology as follows: 1. The skeleton, 2. The sarcodous system, 3. The interstitial canals, 4. The intermarginal cavities, 5. Dermal membrane, 6. The pores, 7. The oscula, 8. Inhalation and exhalation, 9. Nutrition, 10. Cilia, and ciliary action, 11. Reproduction, gemmules, &c.; And to conclude with observations on The generic characters, The specific characters, and On the method of examination. This is the outline of a comprehensive and scientific method of investigation of the Spongiada, undertaken by Dr Bowerbank; and from his well-known microscopic ability, persevering industry, and accuracy as an observer, no one is better qualified for the task, nor more likely to do full justice to it. In the paper referred to, the early stage and development of spicula is described. "They appear to consist of a double membrane, between which the first layer of silex is secreted, and in this condition they present an internal cavity approaching very nearly to the size of their external diameter. In this state they readily bend abruptly in any direction without breaking. An interesting fact, in regard to the animal nature of the sponge, is, that many forms of the spicula have their types in the more highly organised class of animals, and especially among the Zoophyta, the Tunicata, and the Nudibranchiate mollusca. The spicula are always of an organic type, and never crystalline or angular. Each species of sponge has not one form of spiculum only, equally dispersed throughout its whole substance, but, on the contrary, separate parts have each its appropriate form, and three, four, or even more forms often occur in the same individual; and in Tethea cranium there are no less than seven distinct shapes. The spicula appropriate to particular parts of the sponge are uniform in their general characters throughout the whole of the Spongiada, and a great portion of them are so well characterised by their form as to enable the student, when once well acquainted with their peculiarities, to assign each readily to its proper place in the sponge." These organs are treated of in the following order : 1. Spicula of the skeleton. 3. Defensive spicula. 4. Spicula of the membranes. The monograph is accompanied with four beautiful plates, containing upwards of two hundred figures of the different forms of spicula, with a distinct appellation for each form. The scientific world is therefore indebted to Dr Bowerbank for a new arrangement of the Spongiado, with a precise terminology and nomenclature, founded on the anatomical structure and physiology of the species. I have taken this opportunity to give a brief notice of these recent investigations and discoveries, as they are unquestionably the most valuable additions to our knowledge of the Spongiada, since the original contributions of Dr Robert Grant, published in the "Edinburgh Philosophical Journal" for 1826. III. Report of the Committee on Marine Zoology; with a Notice of the Sprat-Fishing in the Firth of Forth. By GEORGE LOGAN, Esq., Con vener. (With exhibition of specimens). Mr George Logan, W.S., the Convener, read the report of the proceedings of the Committee on Marine Zoology for the past year. The Committee, among numerous other captures, obtained a fine specimen of Corystes cassivelaunus, the masked crab, dredged up in Aberlady Bay. Living specimens of Kellia suborbicularis, found plentifully in dead valves of Tapes virginea, near Inchkeith, in September last, lived for rather more than six weeks. Although great numbers of the hermit crab, Pagurus, were examined, dredged in about six fathoms water, in expectation of finding the parasite Peltogaster paguri frequently attached to it, not a single specimen was discovered. Sacculina carcini was found at Trinity attached to the abdomen of the common edible crab, sometimes two or three on one animal. To show how very little particular the hermit or soldier crabs are in the choice of their residence, one was dredged up near Inchkeith ensconced in the large head of an ancient-looking tobacco pipe, covered with barnacles. One specimen of Psammobia Ferroensis was found near Inchkeith; and occasionally on old valves were observed the curious pear shapes, stalked ovarian niduses, of Pontobdella muricata, frequently passed over as the undeveloped state of Himanthalea lorea; some specimens were also procured of Nemertes Borlassii, of a beautiful full dark purple colour, and of enormous length. On the 28th of September four or five specimens of a small flat fish came up in the dredge, which appears to be the Monochirus linguatulus (Cuvier), first observed in this country by Parnell on the Devonshire coast, and noticed by him in 1837 in the Transactions of the |