UNIVALVES .TROCHUS. 109 



the manner in which the raysof tlie sun are often repre- 

 sented in carved work, &c. &c. Added to which, tliereis 

 a most beautiful gold color, which occasionally shines 

 forth through the ochreous surface of the shell, and 

 which of course adds materially to the similitude, in as 

 much as it approaches nearer to the gilded radiance of 

 the splendid orb it is compared with. The Trochus im- 

 perialis, however, has no pretension to a similar appear- 

 ance, for it is mostly of a dull olive color, though there 

 is a rare variety of it, which has a pinkish cast, and is 

 known by the name of the pink sun. They are both rare 

 shells, and from the South seas. 



Among those Trochi which are imperforate, or in other 

 words, those that have their umbilicus closed, may be in- 

 cluded the Trochus vestiarius, Trochus labio, and Trochus 

 tuber, the latter of which very much resembles a turbo. 



The Trochus iris, (commonly called the ear-drop 

 snail), is celebrated, when uncoated, for the splendid me- 

 tallic lustre which illumines its surface; and when held 

 in different positions and lights, exhibits all the varied 

 tints of the rainbow, blended with the richest gold color 

 imaginable. 



The Trochus Cookii, from Cooke's Bay, has its aper- 

 ture closed with a horny lid or operculum, an appendage 

 not unfrequent in many of the Univalve tribes; its use is 

 to secure the inhabitant when retired within its shell; it 

 is affixed to the animal, and as that retreats into the spi- 

 ral whorls of its shell, it draws the operculum in along 

 with it, till arrived at one particular situation of the aper- 

 ture or mouth; where, from the extreme accuracy of its 

 adjustment, it perfectly closes the orifice, thereby form- 

 ing a complete barrier against any outward attacks, that 

 may be made on the animal. 



