Fig. 234. Imperator stella (Lamarck). Fig. 235. Trochus stellaris (Gmel).
The Sun-dial (Solarium), recognized by its deep umbilicus, wide and funnel-shaped, in the interior of which may be seen the little crenated teeth which follow the edge of every turn of the spiral up to the top. In most collections of these pretty shells we find the Staircase-shell (Solarium perspecticum) of Lamarck, from the Indian Ocean (Figs. 236, 237), the diameter of which is sometimes two inches and a half. The Australian Sun-dial (S. variegatum, Linnæus, Fig. 238) is another species frequently seen in collections: it is as much variegated above as below, of a white and rusty brown. The minute trellised Sun-dial, which is only ten lines in diameter, comes from the coast of Tranquebar.
Fig. 236. Solarium perspecticum. Fig. 237. Solarium perspecticum.
Fig. 238. Solarium variegatum.
The eleventh family, Turritellidæ, types Vermetus and Turritella, which last is a numerous family, being found in every sea. All these shells, as their name indicates, represent a winding pyramid, terminating in a sharp point, some of them having fluted spirals, others rounded, angular, or flat, and some of them elegantly pencilled. Figs. 239 to 243 represent some of the varied forms they assume.
