incomparably less bulky, is about one-eighteenth of the length of the head
of a moderately large Balaenoptera rostrata, in which species the baleen is
only nine inches long; so that if we were to make the head of the shoveller
as long as that of the Balaenoptera, the lamellae would be six inches in
length, that is, two-thirds of the length of the baleen in this species of
whale. The lower mandible of the shoveller-duck is furnished with lamellae
of equal length with these above, but finer; and in being thus furnished it
differs conspicuously from the lower jaw of a whale, which is destitute of
baleen. On the other hand, the extremities of these lower lamellae are
frayed into fine bristly points, so that they thus curiously resemble the
plates of baleen. In the genus Prion, a member of the distinct family of
the Petrels, the upper mandible alone is furnished with lamellae, which are
well developed and project beneath the margin; so that the beak of this
bird resembles in this respect the mouth of a whale.

>From the highly developed structure of the shoveller's beak we may proceed
(as I have learned from information and specimens sent to me by Mr.
Salvin), without any great break, as far as fitness for sifting is
concerned, through the beak of the Merganetta armata, and in some respects
through that of the Aix sponsa, to the beak of the common duck. In this
latter species the lamellae are much coarser than in the shoveller, and are
firmly attached to the sides of the mandible; they are only about fifty in
number on each side, and do not project at all beneath the margin. They
are square-topped, and are edged with translucent, hardish tissue, as if
for crushing food. The edges of the lower mandible are crossed by numerous
fine ridges, which project very little. Although the beak is thus very
inferior as a sifter to that of a shoveller, yet this bird, as every one
knows, constantly uses it for this purpose. There are other species, as I
hear from Mr. Salvin, in which the lamellae are considerably less developed
than in the common duck; but I do not know whether they use their beaks for