490 DR. J. MURIE ON THE DERMAL AND VISCERAL STRUCTURES 
Eurypyga and Rhinochetus, excepting size, but presents a marked difference in Can- 
croma. In the two former the left lobe or moiety is smaller than the right, whereas in 
the latter the reverse obtains. The bifid character of the hepatic organ is manifest by 
a deep incision at the upper and lower borders; the surface otherwise is smooth. In 
the Kagu the gall-bladder is roundish; of more elongate figure and larger in the Boat- 
bill. In the first mentioned it occupies a position in a line with the fissures, but is to 
the right of that in the last-mentioned bird. 
The three avine forms compared have each a small, fusiform, less or more elongated 
spleen (Sp, figs. 14 & 20), and attached to the proventricular muscular wall. 
2. Respiratory, Circulatory, and Urinary Apparatus. 
The aperture of the rima glottidis in the Kagu is narrow and elliptical. The thyro- 
arytenoid muscles are tolerably well developed. From the rima back they are divided 
by a deep fissure ; and this and their posterior superficial membranous covering are mar- 
ginally fringed with spines. 
The trachea, 5°6 inches in length, is widest above, and narrows very gradually to 
():2 inch diameter before reaching the usual bifurcate bronchial divisions. In the upper 
third of its course the trachea lies in front, inclines towards the right in the middle, 
and is decidedly to the right side of the fleshy part of the neck at its lowermost third. 
Save less magnitude, the same parts in the Sun-bittern accord with the above. 
The mesial and floor pharyngeal territory, or that intervening between the root of 
the tongue and the fissure of the glottis, is in Cancroma equal to the tongue in length; 
whereas it is no more than a third of the tongue’s length in the two above-mentioned 
species, as in the Gruidz and true Ardeines. In this relation of the parts the ‘ Whale- 
headed” Baleniceps conforms to its broad-billed prototype; and they furthermore 
agree together and differ from the others in a remarkable shortening of the uro-, basi- 
and cerato-hyals. 
The glottidean aperture in the Boatbill appears above as a narrower but somewhat 
longer chink than in the Sun-bittern and Kagu; and the upper larynx is more swollen 
than in them. As in them, however, the calibre of the trachea is greater superiorly 
than inferiorly. Length 7 inches; upper 0°3, and lower diameter 0-2 inch; the nar- 
rowing commences well up, reaches its minimum about the middle of the tube, con- 
tinuing so towards the bronchi. Before divaricating, the trachea exhibits a peaked 
prominence. 
The lungs in all three species present no remarkable features; the intercostal fosse, 
wherein the pulmonary structure is lodged, are shallow. 
The heart (Pl. LVII. fig. 17) apparently differs only in size in the three specimens. 
The aortic arch, as usual in birds, divides into three subequal branches, the innominata 
being very short. 
The Kagu and Sun-bittern possess two glandular structures which are absent in the 
