246 SHOVELLER DUCK. 
very moderate size compared with that observed in many other ducks. 
The rings are 98; those at the lower part broader and much stronger, 
but all of them ossified. The bronchial half rings about 35. 
In another individual, the stomach is 13 inch long, 1,°, broad; the 
right lateral muscle 6 twelfths thick. Contents, particles of quartz, 
and fragments of shells. Intestine 11 feet 6 inches long; cceca 64 
inches long ; rectum 33 inches. 
Long intestines, like long bills, often exhibit great differences in 
the same species ; for which reason characters taken from the length 
of these parts must be received with-latitude. Even in the Rapacious 
Birds, in which the intestine is generally very short, considerable dif- 
ferences are observed in individuals of the same sex and size. It will 
be seen from the above statement that the Shoveller has a longer and 
more slender intestine than any other American duck. In this respect 
it is analogous to Pandion and Haliaetus among the Raptores; gene- 
ralizing vaguely from the consideration of which, as some have done, 
one might be apt to conclude that it is more piscivorous than the 
Canvass-back and Pochard, which however is by no means the case. 
Although in some birds and mammalia a very elongated intestinal 
canal is connected with piscivorous habits, yet many birds which feed 
exclusively on fish, such as Gannets, Auks, and Guillemots, have the in- 
testine of only moderate length or short. It appears simply that when 
for some reason resulting from the economy of the species, the intestine 
must be elongated, it is made proportionally narrow ; whereas if it be 
expedient that it should be short, its calibre is increased. 
