"In the first, the form is very imperfect; it is like a thin cone, and shows no character of the genus; hence young students are perplexed if they chance to have a young cowry in their collection. "In the second state, the shell is still thin, with a _projecting_ spire; but attains its proper form. "In the third, or adult state, the shell is thick, the colours are perfected, and the spire is very nearly concealed. "When the animal becomes too large for its habitation, it has the power of leaving it, and forming a new one.[D] [D] Lamarck. [Sidenote: CYPRÆA.] "The inhabitant of the _Cypræa_ shells has two tentacula of a conic form, and finely pointed; the foot discous, and sometimes tongue-shaped. The mantle is two-lobed, with wing-like margins, capable of being turned back over the shell: this mantle preserves the shell from injury when the animal issues forth in search of food. The genus abounds both in the old and new world; but the larger kind chiefly in warm climates. They live on the coast, and are generally found under stones or rolled coral. A very few species are natives of the European seas. "The tiger-cowry is before you; a large and very common species in collections; it also frequently adorns the mantel-piece. There is a remarkable line extending along the back of the shell; at this part the edges of the _mantle_, that I have before noticed, meet: this line is conspicuous in many species. "_C. aurora_ is a costly shell from Otaheite and New Zealand; the colour orange, with the base and extremities white. It is large, and has been sold for 60_l._ when a specimen has been obtained without any perforation. The shell is worn by the New Zealand chiefs as a badge of honour. "_C. exanthema_ changes its appearance greatly as it advances in growth. While young, three bands extend over the back, which in its adult state disappear, and the fawn-coloured ground is spotted over with numerous white circular marks. [Sidenote: CYPRÆA.] "_C. mauritania_, the moor, is a fine species, with very black sides, and tawny-yellow back with spots. It is a native of Java. "_C. caput-serpentis_, the serpent's-head, has dark sides, with white fauces: the back is covered with net-work colouring: the fauces, you must remember, are the narrow entrances at each end of the shell. "_C. Isabella_, the orange-tip, with pale flesh-colour back, and the fauces orange-colour. "_C. Arabica_ is a common species in collections. "_C. mappa_ is varied with deep brown or yellow lines and spots: the dorsal line is laciniated. "_C. talpa_, the mole, has the back fawn-colour, with three zones of pale yellow; the base and sides sometimes nearly black. It comes from Madagascar. "_C. vitellus_, the fallow-deer, is fawn-colour, covered with small white spots: from the Indian Ocean. "The wasp, _C. asellus_, is white, with three brown bands.