94 THE NAUTILUS. 
covered with a thick tar-colored or very dark green epidermis ; 
interior lined with a dark peach blossom nacre, sometimes salmon 
colored. There is a single, erect, pyramidal, coarsely striated car- 
dinal tooth in the right valve, and two triangular, pyramidal teeth 
in the left valve; lateral teeth long, compressed and slightly curved. 
Length, 33 inches; height, 2 inches; breadth, 1 inch. 
This is our most common fresh-water clam. It is found in all the 
rivers in the U.S. which empty into the Atlantic Ocean, but is not 
found west of the Atlantic slope. It is also abundant in almost all 
the ponds east of the Allegheny mountains. It might be collected 
by bushels in the Blackstone River, Cunliff’s Pond, Old Warwick 
Pond and many others. It is a favorite article of food for the musk- 
rat, which devours them in great numbers, leaving piles of empty 
shells on the edges of the streams and ponds. It is a very curious 
thing how the muskrat can open the sheli and devour the animal 
without leaving a mark of teeth or claw upon the shell. Specimens 
freshly cleaned oftheir contents are in as fine condition for the cab- 
inet as those obtained alive and prepared on purpose, the two valves 
held together perfectly by the ligaments, and the edges or margins 
of the shell unbroken. 
188.— Unio nasutus, Say. 
Syns.: 
Mya nasuta, Wood. 
Eurynea nasuta, Stimp, Perkins, Morse, ete. 
Unio rostratus, Valence. 
Unio nasutus, Say, Con. Lea, Gld. Dall, ete. 
Shell slender, very inequilateral; beaks small, pointed and 
slightly elevated, posterior produced so as to form a snout, from 
which peculiarity its specific name. There are usually two or three 
radiating lines running from the beaks to the end of the snout. 
Surface smooth; epidermis glossy, of a dark olive-green color, 
becoming dusky in old specimens. Nacre silvery white, iridescent, 
sometimes with shades of bluish or salmon; cardinal teeth delicate, 
compressed and directed obliquely forwards; cavity of the beaks 
small, Length, 3.inches; height, 14 inches; breadth, 4 inch. 
Described by Thos. Say in Nich. Ency. 1810. It is quite a com- 
mon shell in the Middle and some of the Western States, but is very 
rare in New Eng. It has been found in only four localities in Mass. 
