OF THE KAGU, SUN-BITTERN, AND BOATBILL. 487 
form; yet his odd expressions are woefully true, as I have seen the bird in its native 
haunts on the White Nile. That “solemn, wise, but somewhat sinister aspect” borne 
by Baleniceps is retained in a manifest degree in Cancroma, though the bird’s dimi- 
nished volume and stature take away from its becoming gravity, and give‘ it a sad 
comical expression in its quiet moments. But its whole demeanour is changed and 
lighted up when the prospect of food arrests its attention. 
With regard to salient resemblances and differences between the bones and beaks 
of the Boatbill, Shoebill, and various Gralline and other forms, Mr. Parker’s remarks 
are all that could be desired. I shall add merely a few notes on my specimen as 
specifying size &c., directing the attention of the reader to the accompanying sketches 
figs. 9 & 10, Pl. LVI. 
The beak of Cancroma is black, more particularly above, but with a yellowish horny 
rim at the lower edge of the premaxillary element and the anterior half. of the lower 
mandible. Length from tip to nasal feathers 3 inches, breadth at the middle 1-6 inch, 
vertical depth at the same place 1°35 inch. The distance between the anterior rim of 
the eyelid, the angle of the gape, and the beak-tip, in each case is 34 inches, from the 
latter point to the posterior end of the nasal aperture 2°8 inches, the length of the 
aperture of the nasal scooping 0-4 inch, the separation between the nostrils 0°6 inch. 
Above there is an interval of 1:4 inch betwixt the eyes. The diameter of the positively 
great eyeball is 1 inch; its anterior surface is about half that behind the nasal orifice. 
There is a well-developed and broad sclerotic ring, which is large, as in the Kagu. 
As Parker has observed, when seen in profile, the dorsal ridge of the beak of the 
Cancroma is convex in its whole extent. In this respect it differs from the central 
gently valleyed and boss-rooted mandible of Baleniceps ; and, moreover, it is still further 
removed from the comparatively ridgeless beak of Ewrypyga and Rhinochetus. 
The very shortened Gallinaceous bill of Psophia is widely distinct from the preceding 
Gralline forms. 
II. VisceraL STRUCTURES. 
1. Mouth and Organs of Digestion. 
The tongue in the Kagu (PI. LVII. fig. 12, ¢) is lanceolate, 2 inches long, with tip 
and under surface horny, grooved above and sharply convex beneath. At the root, 
where the cerato- and basi-hyals join, there is a transverse crenate fold or fringe, its 
concayity being directed backwards. 
The Sun-bittern agrees, excepting that the organ is smaller. Cancroma differs from 
both in having a relatively broader, flat, arrow-shaped tongue (fig. 19, ¢), which, being 
only an inch long, stops far short of the symphysis. It is cartilaginous, excepting the 
outspread angular root-processes, which are soft, fleshy, and smooth-margined. As in 
the Pelican, there is a great, wide inframandibular membrane stretching between the 
rami, and upon which the tongue rests posteriorly; but in the Boatbill it does not form 
