Strombus gallus, or the angel-winged (Fig. 297), veined with stripes of white and red, comes from the coasts of Asia and America. Strombus luhuanus (Fig. 298) is fawn-coloured, marked with white, and externally the right edge is red and striped; inside the columella is shaded purple and black.
Strombus cancellatus, the trellised Strombus (Fig. 299), is small in size and white in colour. Strombus thersites is also represented (Fig. 300).
Pteroceras.
The Pteroceras, from πτερὸν, wing, and κέρας, horn, in many respects resemble the Strombi. They are distinguished from them chiefly in this, that the right edge developes itself with age in long and slender digital spines more or less numerous, the numbers of which vary according to the species. The Pteroceræ are found in the seas of both hemispheres, their vulgar denomination being sea-spiders or scorpions. A glance at the illustrations (Fig. 301, Pteroceras scorpio; Fig. 302, P. millepeda; Fig. 303, P. chiragra; and Fig. 304, P. lambis) will satisfy the reader as to the general correctness of this designation.
Fig. 301. Pteroceras Scorpio (Linnæus). Fig. 302. Pteroceras millepeda (Linnæus).
The genus Pteroceras, whose remarkable form is so well calculated to excite our admiration, has yet another attraction: the colouring of the shell exhibits many shades, which are particularly varied towards the opening, where it is generally distinguished by great freshness and brilliancy, which, added to its other characters, render it the most interesting of all the Gasteropods.
Fig. 303. Pteroceras chiragra (Linnæus). Fig. 304. Pteroceras lambis (Linnæus).