162 MR. W. K. PARKER ON THE OSTEOLOGY 



fronto-lachrymal suture can be seen ; but, for the rest, all is fused, and the lachrymal 

 finishes in front the beautiful sharp-edged superorbital semicircle. In front of the 

 semicircle the lower edge of the lachrymal is incurved ; but there is no trace of the 

 styloid descending process of the Fowl, the thicker rod of the Rail, or the thick 

 cellular mass in which the bone terminates below in the Curassow, Pigeon, Syrrhaptes, 

 and Hemipodius. The basi-temporal region is truly Gallinaceous ; yet there can be 

 detected a manifest lessening of the mass, both centrally and laterally, and a decided 

 approach to what is seen in the Great Rails. The basi-sphenoidal " rostrum " is more 

 smooth and Pigeon-like than in the Fowl ; and the anterior pterygoid processes are 

 more decidedly raised, and a little nearer the pituitary space. So also the counterpart 

 processes on the pterygoid ; they are a little further back, and smaller than in the 

 Fowls, and thus are a step nearer the condition of the like parts in the Pigeon and the 

 Hemipod. But the interorbital septum, rising above the " rostrum," is as smooth, 

 strong, and complete a partition as that of an aged Fowl— far unlike that of the Pigeon, 

 and still further from the great open interorbital space of the Rail. In this latter bird, 

 let it be remarked that the lachrymals are excessively like those of the Safeguard 

 Lizards (Monitor). 



But for the ossification of the great vertical ethmoid, the " Phasianinse " and 

 " Tetraoninse " would come close to the Chelonians in the totally unossified condition 

 of all the " rhinal " structures. The same thing occurs in the Hemipods and Pigeons, 

 save that in them the upper and lower elements of the lateral ethmoids ossify. But in 

 Crax, Talegalla, Pterocles, and Syrrhaptes, we have bone in the inferior turbinal and 

 septal regions. Yet in these parts the Talegalla comes nearer the Weka- Rails {Ocy- 

 dromus) than to its own relatives ; indeed it is, in this respect, one of the most 

 instructive birds in the whole class. It is a remarkable fact that, whilst the ossification 

 and the complexity of the turbinal outgrowths of the nasal sacs are so much simpler 

 and so much less ossified than in mammals, yet the actual continuation of the cranio- 

 facial axis is, in many birds, highly specialized and curiously segmented — so totally 

 unlike the slow osseous degeneration, as it were, to which the middle ethmoid and 

 nasal septum is subjected in the Mammalia. These segments have, however, just as 

 much affinity with vertebrae as the successive pieces that form the digits of the air- 

 breathing Vertebrata and the fin-rays of the Fish. The structure I am speaking of can 

 best be seen in the Guillemot (Uria), the Auk (Alca), the Gull (Larus), and the Ocy- 

 dromus. The middle ethmoid is, as usual, a large bone, and in its alar region directly 

 ossifies about four-fifths of the upper turbinal, which, as in the Rail, is osseous for some 

 distance at its root. The other fifth is formed by a distinct bone, a true prefrontal, 

 and representing the upper half of the Fish's prefrontal, and the delicate band of 

 cartilage which in the Lacertians passes inwards and downwards across the antorbital 

 region. The antorbital, or back of the middle turbinal, is ossified, all but its lower 

 external angle ; this is somewhat in excess of what exists in Ocydromus. 



