Order IV. COLUMB^. 
Family I. Columbid^. 
The fourth Subfamily, 
DIDUNCULIN^, or Tooth-billed Pigeon, 
have the Bill nearly as long as the head ; ^vith the culmen depressed close to the forehead, and then 
suddenly arched to the tip, which is hooked and acute ; the sides slightly compressed ; the lower mandible 
armed with three distinct angular teeth near the tip, which is truncated ; the Nostrils pierced in the 
middle of the basal membranous space, with the opening oblique and linear : the Wings moderate and 
concave : the Tail rather short : the Tarsi moderate, and rather strong : the Toes rather long, and the 
lateral ones equal : the Claws long and curved. 
DiDUNCULus Peale* 
Bill strong, nearly as long as the head ; with the culmen depressed for a very short space, from the 
forehead, and then suddenly rising and forming a prominent arch to the tip, which overlaps that of the 
lower mandible, and is very acute ; the sides slightly compressed ; the lower mandible strong, and fur- 
nished with three distinct angular teeth near the tip, which is truncated ; the gonys short, and curved 
upwards ; the nostrils placed in the middle of the membranous space of the upper mandible, with the 
opening linear and oblique. Wings reaching to the ends of the tail coverts, and concave; with the quills 
acuminated, and the second, third, and fourth nearly equal and longest ; the bend of the wing is armed 
with a blunt tubercle. Tail moderate, and rounded on the sides. Tarsi as long as the middle toe, and 
the front appears to have been covered Avith small scales. Toes rather long, free at their base, and the 
lateral ones equal ; the hind toe long ; and the claws rather long, curved, and acute. The space round the 
eyes, and a small patch on each side of the throat, denuded of feathers. 
The tyi)e of this genus inhabits the Sanioan Islands in the Pacific Ocean. The Rev. J. B. Stair has kindly informed 
me that this curious-billed bird feeds on the roots of bulbous plants. 
D. strigirostris (Jard.) Gould, Ann. Nat. Hist. xvi. p. 175. pi. ix. ; Gould, B. of Austr. v. 76". pi. 
* Establisliud by Mr. Titian Peale. Gnathodon of Sir W . Jardine (1845) and Pleiodus of M. Reichenbach (184? ?) are synonymous. 
December, 1848. 
