prove that we have any very modern evidence of a subsidence of the sea or a raising of the land in the basin of the Forth.* V. (1.) On the Pigmental System of the Equoreal Pipe-fish. By T. STRETHILL WRIGHT, M.D. A few weeks ago I received a specimen of this fish, from Mr Fulton of Granton pier, in a very lively condition. It was placed in a large white vessel of water at ten o'clock at night. The colour of the fish was at that time a dark green, marked with the usual bands. On examining it the next. morning, it had assumed a general hue of bright orange. Towards evening, again, dark-green patches appeared over various parts of the body. It was found the next morning dead on the carpet, having escaped from the vessel in which it was confined, and still retaining the clouded appearance which it possessed on the preceding evening. The pigmental system of the pipe-fish consists of two layers of pigment-cells, which are capable of contracting themselves to mere dots, and of extending themselves until they coalesce. In the outer layer these cells have a darkbrownish green tint; in the inner layer a bright orange. The green cells are excessively branched when dilated. The orange cells tend rather to form uniform expansions. I endeavoured with the utmost care to detect traces of cellwalls in both species of cell, but was unable to do so. The pigment cell appears only to consist of nucleus and contractile protoplasm, and to correspond very closely with the structure of some of the lowest forms of animal life, such as the Rhizopoda. (2.) Description of this Equoreal Pipe-fish. By JOHN ALEXANDER SMITH, M.D. Dr Wright having given me this specimen of the Equoreal Pipe-fish, Nerophis Æquoreus (Kaup.), I thought it might be interesting to add a few details of its description: *Since the above was written, the bed No. 7 of Mr Geikie's section has been nearly all removed, the only portion remaining may be carried away in six or eight cart loads. The section exhibits now, what it did before, that humus and sand were alternate, as the carts which carried the stuff of the foundation were loaded anon with earth and then with sand. Body, octangular; fins, pectoral, anal, and caudal, awanting. Length of fish, 192 inches; length of head, 11⁄2 inch; point of snout to orbit, & inch; front of orbit to extremity of operculum, inch; length from snout to anus, 94 inches; from anus to point of tail, 10 inches; from snout to first dorsal fin ray, 7 inches; length of dorsal fin, 2ğ inches; from last ray of dorsal fin to point of tail, 93 inches. The posterior termination of the dorsal fin is therefore nearly in the middle of the fish. The body consists of twenty-nine rings or divisions, the anus being in the twenty-ninth; the tail of about sixty. No depressions were observed on the abdomen,-probably a female. Dorsal fin, of thirty-nine rays, resting on nine rings of body and two of tail [21st to 31st inclusive]; anus under twenty-eighth and twenty-ninth rays of fin. (For descriptions of other specimens, see pp. 290 and 291). Professor Fleming, in his "British Animals," described this fish as rare, and called attention to the fact of its being "obviously pointed out by Sibbald, as an inhabitant of the Firth of Forth," in 1684. Yarrell also states that examples of this species are rare. VI. Observations on British Zoophytes. (1.) Vorticlava Proteus. (2.) Trichydra pudica. (3.) On the Development of Pycnogon Larva within the Polyps of Hydractinia. By T. STRETHILL WRIGHT, M.D. (1.) Vorticlava Proteus. (Plate XVII.) Scleroderm absent. Colletoderm covering body of polyp. Upper row of tentacles capitate 5; lower row 9. Several specimens of this zoophyte were found in the "Fluke Hole," Firth of Forth. The body of the polyp is exceedingly extensible. At one time a mere button attached to the stone on which it dwells; at another it transforms itself into the various shapes shown in the accompanying figures. A hard covering to the body would necessarily prevent or impede these motions. The scleroderm, therefore, is absent, and the whole body of the polyp is covered with a layer of transparent "colline," which extends from the foot, where it forms a thick mass, to a ridge VOL. II. 3 L which runs beneath the insertion of the lower rim of tentacles. The zoophyte has the power of changing its place. Description of Plate XVII. (Vorticlava proteus.) Fig. 1.-Vorticlava Proteus contracted. Figs. 2, 3, 4, 5.-Same in different states of extension. Fig. 6.-Diagram of the tissues of the polyp of V. Proteus; a a', colletoderm attached to subtentacular ridge b; c, ectoderm; d, endoderm. (2.) Trichydra pudica. (Plate XXII.) This hydroid, which I have already described to the Society, was found completely covering a small shell from the "Fluke Hole." As its mode of reproduction has never been observed, I placed it in a small vessel of carefully-examined sea-water, and exposed it to light, a mode of treatment which often induces the Hydroida to assume their medusoid phase. After some time, two small medusoids were found in the water, but I was unable, by the most careful examination, to detect their mode of development, as no gonophores" appeared on any part of the cœnosarc. The connection of these medusoids with Trichydra is yet open to doubt, although I am convinced that no other zoophyte occurred on the shell, or in the water in which it was placed. Medusoid of Trichydra pudica ?—Umbrella mitre-shaped, covered with minute thread-cells. Sub-umbrella with four lateral canals, destitute of ovaries or sperm sacs. Peduncle short, cylindrical, four cleft at the mouth. Tentacles four, short, with two or four intervening tubercles. absent, eye-specks absent. Description of Plate XXII. (Trichydra pudica.) Fig. 1.-Polyp extended, showing the lax habit of the zoophyte. Fig. 3.-Young Polyp. Fig. 4.-Polyp within its tube. Fig. 5.-Empty cell. Fig. 6. Supposed medusoid. Oolites (3) On the Development of Pycnogon Larva within the Polyps of Hydractinia echinata. In a communication made by Professor Allman to the British Association in 1859, entitled, "On a remarkable form of Parasitism among the Pycnogonidae," the author de scribed the occurrence of certain vesicles on the branches of the Coryne exima, which, although possessing a strong resemblance to the reproductive sacs of the zoophyte, and formed of all the proper tissues of the cœnosarc and its coverings, were distinguished from those organs by each enclosing a single living Pycnogon, which, in the smaller vesicles, was embryonic, while in the larger it presented an advanced stage of development. A similar observation was made by Mr G. Hodge (Ann. and Mag. N. Hist., ser. 3, vol. ix.), who considered that the sacs were modified or stunted branches of the Coryne, the development of which had been arrested by the presence of the enclosed Pycnogon. On reading the papers of these gentlemen, I remembered that I had, some time before, been much puzzled by the discovery of armless Pycnogons resembling Mr Hodge's figure (pl. iv. fig. 10, op. cit.) in several altered polyps of a specimen of Hydractinia. In this case two or three were found in each polyp, which had assumed the form of a dilated and transparent sac crowned by its usual tentacles. The polyps appeared to be bloated and overgrown under the use of their Pycnogon diet. Mr Hodge's paper at once set me on the look-out for another specimen of Hydractinia tenanted by Pycnogons, and this I at last obtained by the kindness of my friend, Dr Wilson, Demonstrator of Anatomy at the University of Edinburgh. In this, one of the polyps contained three larvæ of a pale yellow colour, which appeared, as far as could be seen without injuring the polyp, to be destitute of legs. When first observed, the polyp was furnished with its proper complement of tentacles; but as the development of the Pycnogons proceeded, the tentacles were absorbed, and the polyp became a long sac pointed at its upper extremity, and fitting closely on its contents, which appeared to be embedded in the longitudinal folds of the highly-developed endoderm. Mr Hodge supposes that the larvæ, at a very early stage, are swallowed by ordinary alimentary polyps of the Coryne, and carried through the tubes of the cœnosarc, until they arrive at a part which is about to become a polyp, which thereupon has its destination altered. And I think there can be little doubt that his surmise is correct, as in Coryne all Pycnogon sacs, in all stages of development, are not only destitute of tentacles, but are, according to Professor Allman, covered by a layer of the chitinous polypary or scleroderm. Such a mode of nidification, however, could not take place in Hydractinia, the cœnosarcal tubes of which are of exceedingly small calibre. Accordingly, we find that the Pycnogon sacs in this zoophyte are formed, not by the arrest or change in development of an immature polyp, but by the degeneration of a tentacled polyp previously perfect. Perhaps I ought to mention here, that globular sacs are occasionally found in place of the polyp, in Coryne glandulosa (Dalyell). These are destitute of scleroderm, and lined with a very dense brown endoderm, arranged in somewhat reticulated folds. As far as I observed, they were empty, and, by constantly undergoing alternate processes of dilatation and contraction, appeared to influence the circulation of the zoophyte, It is possible that minute Pycnogons may have existed in these sacs. VII. Report of the Committee on Marine Zoology. By GEORGE Logan, Esq., W.S., Convener. (Specimens were exhibited.) The Committee had several excursions in the Firth of Forth during the past season, and were occupied in trawling and dredging, and also in sweep-net fishing on the shore. Upon the 11th of May last, among numerous specimens of Mollusca procured off Inchkeith, the following only were worthy of notice; recorded by Dr. M'Bean:- 1st, The bivalve, Cardium norvegicum of Spengler, alive; 2d, The bivalve, Montacuta substriata of Montagu, also alive, on Spatangus purpureus; 3d, The univalve, Apenhais pes pelicani of Linnæus, alive, it lived until the 10th of September; 4th, The univalve, Pileopsis Hungaricus, or Fools-cap limpet,-it was also alive upon Modiola modiolus, and lived until the 20th of June; and 5th, The Echinus thyone papillosa, which spawned upon the 18th of June, and died next day. Mr William S. Young recorded a specimen of the Psolus phantapus, which came up upon a baited line near Inch |