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 (Pis. XXXIV. & 

 XXXV. n.), the frontals (/.) 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 Struthionidae (PI. XLII. 

 fig.4n.), 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 (Pis. 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 " Gallinaceee " not forking abruptly and at 

 a sharp angle, but having, as it were, their anterior margin so scooped out as to leave 

 an upper and an under sharply-pointed process. 



Like the Syrrhaptes and the Pterocles, the Hemipodii 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 (Pis. 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 

 (PI. XXXVI. figs. I &2), and to a less degree in the Common Pigeon {Columba livia) 

 (PI. XXXVII. figs. 6 & 8). But in that sudden concavity of the outline below of the 



