Rock Shells. 49 
it is strong and firm, from three to four inches long, 
of a dirty yellowish white. There are two other 
Whelks common upon our coasts—the Stone or 
Dog Whelk (B. lapillus), from the Latin lapis—a 
stone ; and B. reticulatwm, so called because the shell 
is reticulated, or marked with many lines crossing 
each other, like net-work; it comes from the Latin 
reticulum—a net; hence also we have reticule—a 
small work-bag, at one time very much carried by 
ladies. 
ROCK SHELLS, 
Are so called on account of their rough and wrink- 
led forms ; they are nearly allied to the Whelks, to 
which they bearaclose resemblance. Several species 
are found on our shores, the most common being 
the Humble Murex (M. despectus), from the Latin 
despecto—to despise; this is often used by the 
fishermen for bait. Some of the foreign Rock 
Shells are very curious and beautiful; three of 
them will be found on Plate II., Figs. 1, 2, and 3. 
The Common Thorny Woodcock (M. tribulus), from 
the French for trouble, whence we have also tribu- 
lation, which is sometimes said to be a thorny path. 
This curious shell is also called Venus’ Comb. It 
