334 BIRDS. 
Cancroma, Linn. 
The Boat-bills, which would closely approach the Herons in the strength 
of their bill and in the regimen resulting therefrom, but for the extraor- 
dinary form of that organ, which we shall find, however, by close examin- 
ation, to be nothing more than the bill of a Heron or Bittern, very much 
flattened. In fact, it is very wide from right to left, and is formed like 
two spoons, the concave sides of which are placed in contact. The man- 
dibles are strong and trenchant, the upper one having a sharp tooth on 
each side of its point; the nostrils, situated near its base, are continued 
on in two parallel grooves to near the point. There are four toes to the 
feet, long, and almost without membranes, and accordingly we find that 
these birds perch upon trees on the banks of rivers, whence they preci- 
pitate themselves upon the fish, which constitute their customary food. 
Their gait is slow, and, in their attitudes, they resemble the Herons. The 
species known is, 
Cancr. cochlearia, L.; Enl. 38 and 369; Vieill. Gal. pl. 249. 
(The Boat-bill). Size of a hen; whitish; grey or brown back; red 
belly; a white forehead, followed by a black calotte, which, in the 
adult male, is changed into a long tuft: inhabits the hot and marshy 
parts of South America, 
Then comes, 
ArptEA, Cuv. 
Or the Herons, the cleft of whose bill extends to beneath the eyes; a 
small nasal fossa continuing on in a groove close to its point. They are 
also distinguished by the internal edge of the nail of the middle toe, which 
is trenchant and denticulated. Their legs are scutellated; the thumb and 
toes tolerably long, the external web considerable, and the eyes placed in 
a naked skin which extends to the bill. Their stomach is a very large, 
but slightly muscular sac, and they have but a very small cecum. 
They are melancholy birds, which build and perch on the banks of rivers, 
where they destroy great numbers of fish. Their dung burns the trees. 
There are many species in both continents, which can only be divided by 
a reference to some details of plumage. 
The true Herons have a very slender neck, ornamented below with 
long pendent feathers. 
Ard. major and Ard. cinerea, L.; Enl. 755 and 787; Frisch, 198, 
199; Naum. Ed. I. 25, f. 33, 34. (The common Heron.) Bluish 
ash colour; a black tuft on the occiput; forepart of the neck white, 
sprinkled with black tears; a large bird, whose depredations on the 
fish, in the rivers of Europe, render it highly prejudicial. It was 
formerly much celebrated for the sport it afforded to falconers. 
Ard. purpurea, En). 788; Naum. Ed. I. Supp. 45, f. 89, 90*. 
* The Ard. purpurea, purpurata, rufa, Gm., and the africona, Lath., according to 
Meyer, are mere varieties of the purple Heron. 
Add, A. herodias, Gm.; Wils. VIII, lxv, 2, the young of which is, perhaps, Enl. 
858;—A. cocoi, Lath.; Spix, XC, under the false name of Ard. maquari;—A. sibila- 
