512 MR. W. K. PARKER ON THE OSTEOLOGY OF THE KAGU. 
The Ewrypyga is very typical in having a long neck, and very curiously isomorphic 
of the Anhingas (Plotus) in the unusual elongation of this part'; for whilst it has five 
more joints in this region than the Green Bittern, it has the individual vertebree as long 
as in that true Ardeine bird. Yet this elongation of the cervical vertebra, a most con- 
stant character in the true Ardeini, is not coupled with the swollen, spongy condition 
seen in those birds, but the bones are quite Gruine in their histological characters. 
But the Kagu differs from all its congeners in the stoutness of its cervical vertebrie 
(Pl. XCI. figs. 1, 2); this is a correlate of its very large ridgy head, and is similar: to 
what is seen in the Baleniceps. This incrassation of the cervical vertebre is coupled 
with a diminution of their number; and the strength of the head and neck of this bird 
is in curious contrast with the feeble condition of many other parts of the skeleton. 
In the cervical vertebree, as in the rest of the skeleton, the Kagu shows a very much 
feebler ossification (especially with relation to the fibrous bands that are attached to 
the bones) than the Psophia and the typical Cranes ; in this it agrees with the Eurypyqa; 
and the difference between the vertebre of these two types is merely such as arises from 
the slenderness of those of the Sun-Bittern and the breadth and shortness of those of 
the Kagu. 
The “atlas” of the Kagu (Pl. XCI. figs. 1 & 2, and Pl. XCIL. figs. 12 & 12a) isa 
strong ring of bone; its upper portion projects on each side behind; its centrum is tri- 
dentate; and it has the “cup” cut away in a rounded manner for the “ odontoid process 
of the axis.” 
The * axis” (Pl. XCI. fig. 1 and fig. 2, 13, and Pl. XCII. figs. 13, 13 a, 13 4) has a thick 
upper and a triangular lower spine; over each of its oblique facets there is a thick ridge; 
and there is a small bony bridge on each side of the odontoid process (Pl. XCII. figs. 13a, 
150). 
The next vertebra (Pl. XCII. figs. 14, 14 a, 14 6, 14 ©) is intermediate in shape between 
the “axis” and the ceryicals of the hind region; its spine is smaller than that of the 
“axis,” it has a short, stout rib, confluent with the sides of the bone and forming a 
bridge for the vertebral artery. The next ten vertebre have scarcely any spine; the 
sixth approaches in character the typical form of those of the hind region (Pl. XCI. 
figs. 1 & 2,15, and Pl. XCII. figs. 15, 15 a@,.15, 15c). In this bone the transverse pro- 
cesses project considerably; there is no process tending to wall-in the carotid artery 
below; the centrum is deeply concave beneath, and is produced into two ears behind, 
the transverse convexo-concave hinge being greatly produced outwards. The next four 
have paired processes, tending to embrace the carotid artery; the penultimate bone of 
these (Pl. XCI. figs. 1 & 2, 16,and Pl. XCII. figs. 16, 16 a, 16 6, 16 ¢) is seen to be of great 
breadth, and rather short, with its oblique facets very diverging. In the next five joints, 
instead of the paired “carotid processes,” there is a flat inferior spine; in these the 
The abortion of the “ ethmo-presphenoidal” band in the Sun-Bittern is in harmony with what we see not 
only in the Stilt-Plover but also in the Cormorant. 
