UNIVALVES. TURBO. 107 



Perversus — Reversed. Flumineus — River. 



Pusillus — Minute. Punctatiis — Dotted. 



Undulatus — Waved. Striatellus — Violet-tip. 



Ventricosus — Ventricose. Ziczac — Zigzag. 



Ann ulatus — Ringed. L unaris — Convex. 



Hortensis- — Garden. 



TURBO— Wreath. 



Animal^a Limax: Shell univalve., spiral, solid; aper- 

 ture contracted, orbicular, entire. 



There are no less than one hundred and tifty- three spe- 

 cies of this beautiful genusi wliich are, for the most part, 

 solid and ponderous shells, and many of them of a pearly 

 nature when uncoated. They resemble tlie Trochus in 

 form, but may easily be distinguished by their suborbi- 

 cular aperture. 



The first division has the pillar margin of the aperture 

 dilated, and the pillar imperforate. Among the leading- 

 species may be enumerated the T. obtusatus, T. neri- 

 toides, and the T. littoreus, or common periwinkle, a 

 well known British shell : its fish, when boiled, is not 

 unfrequently eaten. It is an inhabitant of most Europ- 

 ean shores; and it is said of them by sailors, that, if seen 

 crawling high up the rocks, it is an indication of the ap- 

 proach of stormy weather; but if, on the contrary, they 

 descend, a calm may be expected. 



The next division consists of the solid and imperforated 

 species: among the principal are the T. petholatus, T. 



