ALCEDO BIRU. 
the genus into two sections, founded on certain differences which exist in the form 
of the bill. After continued inquiries, and the examination of subjects from other 
parts of the world, I can now state with confidence, that the characters of each of 
these sections are sufficiently marked and permanent to sanction a separation into 
two distinct genera, the peculiarities of which I shall now enumerate. 
In the first the bill is very long, slender, gradually attenuated to a sharp point, 
compressed to such a degree that the height considerably exceeds the breadth, 
having both mandibles carinated, and marked with longitudinal grooves, and the 
cutting edges, or tomia, slightly bent inwards. The Alcedo Ispida furnishes a 
sample of this genus. In the second the bill is of a light consistence, greatly 
distended, broad at the base, and gradually tapering towards the extremity, which 
is moderately compressed. The upper mandible is even, or very slightly grooved 
from the nostrils to the point; the back, or culmen, is rounded, not prominent or 
keeled, and the extremity of the upper mandible forms a cavity for the reception of 
the lower: the latter is depressed at the base, swelled towards the middle, then 
gradually attenuated to a point, which is acute, and somewhat smaller than the 
upper. The cutting edges, tomia, are sharp; those of the upper mandible are 
slightly curved, while those of the lower are straight : near the tip the upper man- 
dible is slightly bent downwards, while the lower inclines upwards in a small degree. 
The Alcedo sacra furnishes a sample of this genus. 
Besides these, a third natural division of Alcedo, as it was defined by the earlier 
Ornithologists, is afforded by the Gigantic Kingsfisher of New Holland. For 
this the name Dacelo was proposed by Dr. Leach, and it has received the sanction 
of the celebrated Temminck, in the "Analyse du Systeme general d'Ornithologie," 
prefixed to the Second Edition of liis Manuel. The bill in this genus does not 
exceed the head in length, and it is stronger and more dilated than the bill of the 
individuals belonging to the second genus. The cutting edges, towards the extre- 
mity, take a bold curve upwards, and are deeply cut out ; the tip is greatly length- 
ened, and terminated by a small notch. The lower mandible is considerably swelled; 
the margin is not straight, but curved upwards, to meet the curve of the upper 
mandible. A new species, the Dacelo pulchella, described in the Second Number 
of these Researches, has lately been added to this genus from Java. 
The propriety of these views, as far as regards the division of Alcedo, of the 
earlier Ornithologists into two genera, is confirmed by the Author of the Zoolo- 
gical Illustrations, William Swainson, Esq. In the Fifth Number of this work, the 
second genus is described with the name of Halcyon, while Alcedo is applied to 
