180 MR. W. K. PARKER ON THE OSTEOLOGY 
line. At its base, this lamina is pedate, the foot-like process turning outwards. 
Between the aliethmoid (which is convex in front and hollow within) and the oval 
turbinal, there is a free space separating the two ; the large end of the olfactory crus lies 
in this space. All these osseous developments of the nasal labyrinth of the Hemipodius 
impinge upon the space required by the Schneiderian membrane, instead of assisting to 
any extent to form surface-room. This condition, so unlike the rhinal outgrowths of 
the Mammal, is very much like the simplicity of these parts in Lizards; whilst the 
solid prefrontals almost rival, in rudimentary simplicity, those of Fishes. All the 
middle of the anterior part of the frontal region is formed in Pigeons and in the 
Hemipodius by the broad cellular posterior portion of the nasals (Pls. XXXIV. & 
XXXV.n.), the frontals (f.) being mere strips of bone on each side. The nasals 
bifurcate just where the frontals end, one process running forwards close to the nasal 
process of the premaxillary, whilst the other passes downwards and forwards to the so- 
called maxillary. This latter process is in some degree a measure of the height of the 
bird in the zoological scale; for it is abortive in the typical Struthionide (PJ. XLII. 
fig. 4 n.), extremely small and delicate in Tinamous and Syrrhaptes, a little stronger in 
Hemipodius, and stronger still in the Fowls, Pigeons, and Plovers. In the latter groups 
it is a highly characteristic process; for it is flat and lath-like in Fowls, thicker and 
cellular below in Pigeons, narrow and oval in section in Plovers. Between the forks 
of the nasal bone the aliethmoid can be freely seen in Pigeons, Sandgrouse, and the 
Hemipodii as a convex cellular plate (Pls. XXXIV. & XXXV. fig. 3); only a small 
portion can be seen in Vanellus, and that thin and fibrous like the rest of that bird’s 
skull. The extreme thickness of the cellular descending process of the nasal in the 
Dodo hides the view of the aliethmoid in this aspect. This is but an exaggeration of 
a Pigeon-character in that massive bird. In the Fowl-tribe the aliethmoids are feebly 
ossified, but their cartilaginous margins are roofed-in above by the broad prefrontal 
portion of the nasals,—these bones in the “‘ Gallinaceze” not forking abruptly and at 
a sharp angle, but having, as it were, their anterior margin so scooped out as to leave 
an upperand an under sharply-pointed process. 
Like the Syrrhaptes and the Pterocles, the Hemipodw are quite columbaceous in 
this part of their skull; what falling-off there is from that type is a leaning towards the 
Plovers, and not towards the Fowls. Curious to relate, the premaxillaries, as well as 
the mandibles, are very Gallinaceous in aspect; and the open nasal fossa in the dry 
skull is as wide as in the Quail (Pls. XXXIV. & XXXV. fig. 4). 
The Hemipodius varius is more “‘ pressirostral,” has a more compressed beak than the 
smaller species, and it especially reminds one of the Didunculus. There is, however, in 
both the absence of that pinching-in of the whole upper jaw behind the solid part 
of the premaxillaries which is seen so markedly in the Dodo and the Syrrhaptes 
(Pl. XXXVI. figs. 1 & 2), and to a less degree in the Common Pigeon (Columba livia) 
(Pl. XXXVII. figs. 6 & 8). But in that sudden concavity of the outline below of the 
