96 Beautiful Shells. 
aloud snap; so that you see these sober-looking 
mollusks are sometimes frolicsome fellows: this is 
an enforcement of the lesson, judge not by appear- 
ances. 
Some of the species, both of the Mussel and 
Cockle families, have very beautiful shells. We 
give a representation of one of each, on Plate VIII. 
Fig. 2 is the Magellanic Mytilus, (IZ. Magellanicus,) 
found chiefly in the Straits of Magellan ; it is gene- 
rally four or five inches long; the shells when 
polished are very brilliant, the deep purple colour 
changing into rich violet, as they are held in 
different lights. In most cabinets the large fan- 
like delicate shells of the genus Pinna may be 
observed; the largest species is that called Pinna 
flabellum, taken in the Mediterranean; it sometimes 
exceeds two feet in length. The first of these 
names is a Latin word signifying, besides a shell- 
fish, the fin of a fish, or the wing-feathers of a bird 
—hence the term pinion; it refers to the fin-like 
or wing-like shape of this shell. Flabellum means 
a fan, referring probably to the bissus of the mol- 
lusk, which is fine and glossy, like silk, and very 
abundant. 
Many pretty specimens for figuring might be 
sclected from the Naide, a family of Fresh-water 
