{37} _Sertularia operculata_ and _Gemellaria lociculata_; or any of the small _Sertulariæ_, compared with _Crisiæ_ and _Cellulariæ_, are very good examples. For a fuller description of these, see Appendix explaining Plate I. {67} If any inland reader wishes to see the action of this foot, in the bivalve Molluscs, let him look at the Common Pond-Mussel (Anodon Cygneus), which he will find in most stagnant waters, and see how he burrows with it in the mud, and how, when the water is drawn off, he walks solemnly into deeper water, leaving a furrow behind him. {70} These shells are so common that I have not cared to figure them. {72} Plate IX. Fig. 3, represents both parasites on the dead Turritella. {74} A few words on him, and on sea-anemones in general, may be found in Appendix II. But full details, accompanied with beautiful plates, may be found in Mr. Gosse’s work on British sea-anemones and madrepores, which ought to be in every seaside library. {90} Handbook to the Marine Aquarium of the Crystal Palace. {111} An admirable paper on this extraordinary family may be found in the Zoological Society’s Proceedings for July 1858, by Messrs. S. P. Woodward and the late lamented Lucas Barrett. See also Quatrefages, I. 82, or Synapta Duvernæi. {113} Thalassema Neptuni (Forbes’ British Star-Fishes, p. 259), {116} The Londoner may see specimens of them at the Zoological Gardens and at the Crystal Palace; as also of the rare and beautiful Sabella, figured in the same plate; and of the Balanophyllia, or a closely-allied species, from the Mediterranean, mentioned in p. 109. {118} A Naturalist’s Rambles on the Devonshire Coast, p. 110. {121} Balanophyllia regia, Plate V. fig. 1. {126a} Amphidotus cordatus. {126b} Echinus miliaris, Plate VII. {127} See Professor Sedgwick’s last edition of the “Discourses on the Studies of Cambridge.” {129} Fissurella græca, Plate X. fig. 5. {130a} Doris tuberculata and bilineata. {130b} Eolis papi losa. A Doris and an Eolis, though not of these species, are figured in Plate X. {136} Plate III. {138} Certain Parisian zoologists have done me the honour to hint that this description was a play of fancy. I can only answer, that I saw it with my own eyes in my own aquarium. I am not, I hope, in the habit of drawing on my fancy in the presence of infinitely more marvellous Nature. Truth is quite strange enough to be interesting without lies. {139a} Saxicava rugosa, Plate XI. fig. 2. {139b} Plate VIII. represents the common Nassa, with the still more common Littorina littorea, their teeth-studded palates, and the free swimming young of the Nassa. (_Vide_ Appendix.) {140a} Cypræa Europæa. {140b} Botrylli. {140c} _Molluscs_. Doris tuberculata. Sigaretus. — bilineata. Fissurella. Eolis papillosa. Arca lactea. Pleurobranchus plumila. Pecten pusio.