FIG. 1. Grantia compressa 2. Euglena viridis 3. Dinobryon sertularia 4. Synura uvella 5. Peridinium tabulatum 6. Coleps hirtus 7. Trachelocerca viridis 8. Trachelius ovum 9. Amphileptus gigas 10. Bursaria Mülleri 11. Folliculina elegans 12. Stentor polymorphus 13. Trichodina pediculus 14. Vorticella nebulifera 15. Zoothamnium arbuscula 16. Do. do. contracted 17. Vaginicola crystallina 18. Ophrydium versatile (colony) 19. Do. do. (single zoöid) 20. Cothurnia imberbis 21. Pyxicola affinis 22–23. Stylonychia mytilus 24. Acineta grandis 25. Loxophyllum meleagris 26. Euplotes charon (dividing) 27. Chætonotus larus [Illustration: XIII.] The inhabitants of these shells are Amœbæ, mere masses of jelly, and some forms may be found sliding over the weeds in almost every rock-pool. The anchor-mud, already spoken of, always contains some, and many forms may be found in the sand from sponges, which should be passed through a series of wire sieves, of increasing fineness, and the residuum in each case be examined dry under a one-inch power. The shells may be picked up with a needle which has been slightly greased by being passed over the hair, and they may be mounted by sticking them to the slide with thin starch paste, putting on a cover-glass properly supported, and then running turpentine under the cover-glass, heating to expel the air, and finally filling up with balsam. Or, as opaque objects, they may be mounted in a cell dry. The forms are endless, but all are beautiful, and a few examples are given in Plate IX. Fig. 4 (_Miliolína_), and Plate XII. Fig. 7, which is a portion of the shell to show the holes, Fig. 13 (_Polystomella_), Fig. 14 (_Truncatulína_), Fig. 15 (_Polymorphína_), Fig. 16 (_Miliolína_, partly fossilised), Fig. 18 (_Lagéna_). and Fig. 20 (_Biloculína_). Allied to these are the lovely Radiolaria, whose shells, constructed on a similar plan, are composed of flint. They are found in remarkable profusion in the deposit from Cambridge, Barbados, but also in a living state at even enormous depths in the ocean. The present writer has obtained many forms from _Challenger_ soundings, and the great authority on this subject is Haeckel’s report in the official accounts of the expedition of the above-named vessel. The Hydroid Zoophytes are represented by several examples. These creatures are soft and almost gelatinous, and are furnished with tentacles or lobes by which they can catch and retain their prey. In order to support their tender structure they are endowed with a horny skeleton, sometimes outside and sometimes inside them, which is called the polypidom. They are very common on our coasts, where they may be found thrown on the shore, or may be dredged up from the deeper portions of the sea.