182 MR. W. K. PARKER ON THE OSTEOLOGY 
or the Syrrhaptes (Pl. XXXVI. fig. 1), and less thick and clumsy than it is in the 
Fowl-tribe (PI. XXXVI. fig. 6). It is most like that of the Lapwing; but its sphe- 
noidal or middle facet is relatively larger, and the whole bone is broader, although it 
has the same thin, sharp-edged character. Posteriorly the pterygoid articulates by a 
double condyle with the os quadratum ; this articular surface is concave beneath, whilst © 
above, at the end of its upper process, the facet is slightly concave across and con- 
vex vertically. This double articulation of the pterygoid with the os quadratum is 
found also in the congeners of Hemipodius, viz. the ‘‘ Galline,” ‘‘Columbine,” and 
** Pluvialine.”” 
The os quadratum (q.) is intermediate between that of the Pigeons (Pl. XXXVI. fig. 6) 
and Plovers (P]. XX XVII. fig 1). The double upper articular head is perfectly normal, 
and not single, as in the ‘‘ Gallinacez,”’ where the homologue of the posterior crus of the 
‘‘incus’’is aborted. The orbital process is intermediate in breadth between the Plover, 
where it is broad, and the Pigeon, in which it is narrow—not so narrow, however, as in 
the Fowls. There is nosuch process on the incus of Mammals. In the breadth of the 
internal, convex articular surface for the lower jaw the os quadratum of the Hemipo- 
dius is also halfway between that of the Plover and Pigeon, it being broader than in 
the latter and narrower than in the former; the external facet is similar in all three 
(Pls. XXXIV. XXXV. & XXXVII.). The deep pit for the incurved end of the qua- 
drato-jugal (q.7.) is strictly pluvialine, this articulation being shallow and oblique in 
the Fowl-tribe and Pigeons. The lower jaw of Hemipodius 2 is an almost exact 
counterpart of that of the Ptarmigan (Lagopus), being much stronger than that of the 
Quail, Pigeon (PI. XX XVII. fig. 9), or Plover (PI. XX XVII. fig. 4). Perhaps the angle 
at which the rami meet is a little more acute than in the Ptarmigan, and the angular 
processes, especially the internal, are shorter and thicker relatively. The large mem- 
branous space of the ramus is quite equal to what is found in Lagopus (Pl. XXXVI. 
fig. 9); in the Pigeon it is almost obsolete, and in the Lapwing small and oval. The 
coronoid process of the surangular is very strong—as strong as in the Grouse. The 
articular facets are also more like those of the ‘‘Tetraonide”’ than those of the 
Pigeons or Plovers. The dentary elements are short in Pigeons, longer in Plovers, 
very long in the Tetraonide (Pl. XXXVI. fig. 9). The posterior part of the ramus in 
Pigeons (the articulare, with its investing splints, the angulare, and surangulare) is very 
thick and cellular—very different from the condition of this part in Lagopus, Hemi- 
podius, and Vanellus. In the Syrrhaptes this part is intermediate between that of 
Pigeons and Grouse. 
The ‘‘ os hyoides”” has not been preserved in either of the skeletons of Hemipodius 
under inspection. 
In Hemipodius varius (Pl. XXXV. fig. 5) I find nineteen vertebre between the skull 
and the sacrum (Professor Owen gives eighteen; see ‘Cat.,’ p. 274), and in the smaller 
species there are twenty. In the latter kind the last sacral vertebra is (in this specimen) 
