Birds of Massachusetts. 249 
The Pre» Dock, Z'uligula Labradora, is thought, 
by Nuttall, to belong to the western part of the 
continent, and to be only found as a straggler on the 
Atlantic shores. Ttis called the Sand-shoal Duck, by 
the gunners of the middle states, from its resorting to 
sand bars in search of food. It is rarely found in 
this State, and only in winter or spring. 
The Cawvass-sAck Duck, Fuligula valisneria, 
so well known as a luxury of the table, never 
abounds in Massachusetts; some are seen in winter 
near Cohasset and Martha's Vineyard, and I learn 
from Mr. Cabot, that it has been shot in Fresh Pond. 
The great proportion, however, on returning from 
the fur countries, where they breed, establish them- 
selves on Chesapeake Bay and the neighboring wa- 
ters, and thence extend to the south ; some having 
been seen, in winter, as far as New Orleans. The 
fresh water plant, valisneria, from which they are 
named, is their favorite food ; it grows in long, nar- 
row blades, with a white root, which is the part that 
they eat; they swim about the shoals where it 
grows, diving and tearing it up, not discouraged in 
consequence of the losses which they suffer from 
the dishonest arts of the widgeon. But where this 
plant is not found, they feed on the eel-grass, as it 
is called, which affords a subsistence to the canvass- 
back, and other birds of a similar description. 
Though these birds, when they first arrive, are 
lean, in consequence of exhaustion, they are so dili- 
gent in collecting food that they soon are in order 
VOL. III.—NO. 1—II. 
