486 DR. J. MURIE ON THE DERMAL AND VISCERAL STRUCTURES 
The upper mandible is quite flat above at its middle third; and the peculiar nostril- 
lids give prominence and breadth to the basal part. 
The openings of the nostrils in most of the Ardeidz are situated proximally to the 
length of the beak. Such is the case in the Kagu. In it each orifice is 0-7 inch long, 
and provided superiorly with an elliptically shaped fold of tough cutaneous membrane, 
coloured like the horny beak. The said overhanging membranes form two scroll-like 
lids, hinged or attached above. ‘These protect the external nares without entirely 
closing them while the beak is not in use’. 
The legitimate use of these lids, however, appears to be prevention of foreign matter 
entering the nostrils when the bird, as is its habit, digs into the soft soil for its food’. 
The manner of closing the above nasal apparatus is as follows:—As the nostril 
approaches the ground and is touched, its anterior part, having a plough-share forma- 
tion or scroll-like contour, sends the earth upwards or over it. The springy semi- 
elastic lid, from in front to behind, is pressed down and inwards, finally completely 
closing the aperture as the beak is thrust deep into the earth in search of its living 
prey. 
Eurypyga, in the comparative length to breadth of the beak, approaches more to 
the true Herons than does the Kagu; the latter has semblance rather to the Night- 
Herons. Neither has the Sun-bittern the anterior depressed curve of beak of the two 
last-mentioned forms. In Hwrypyga the beak at the sides is more compressed ; the 
dorsal ridge is sharper, and it wants the upper flattening present in the Kagu. The 
nostrils are simple, narrow, longitudinal slits, each 0:25 inch long, and they are not 
protected by a lid, the upper margin being rigid as is common in the Ardeines. 
The simplest statement of a comparison between the bills of Cancroma and the two 
preceding genera is to say that they are totally unlike each other. From the pickaxe- 
model of the Kagu’s beak, so admirably adapted for thrusting and digging into soft 
soil, we find a reduction as to strength, form, and purpose in the more elegant-beaked 
Sun-bird. In the Boatbill, however, true to its name, an entire reversal in the figure 
of the premaxillary region gives to the beak that character whereby the bird is known, 
and, significantly unfitting the bill for instrumental use as a sharp earth-cleaver, trans- 
forms it into a grappler of fish. 
Mr. Parker, in his valuable Osteology of the Shoebill (Baleniceps rex)*, doubtless 
was in one of his playful moods when describing the premaxilla of that extraordinary 
' One of the American Rails is distinguished from its fellows by a nasal appurtenance somewhat similar 
in kind to that of the Kagu, this minor link establishing structural approximation. In their ‘Synopsis of 
the American Rails’ (2allide), Messrs. Sclater and Salvin on this account exclude from Porzana the species 
shomburgki, ranking it as a separate genus, Thyrorhina.—P. Z. 8. 1868, p. 458, fig. 1, upper and profile 
view of head. 
* Mr. Bartlett succinctly, but graphically, describes the bird’s manner of feeding, its grubbing up earth- 
worms with evident relish_—See P. Z. 8. 1862, p. 219. 5 Trans. Zool. Soe. vol. iv. 
