314 DR. GADOW ON THE ANATOMY OF PTEROCLEs. [Mar. 21, 
The general coloration of the Sand-Grouse is thoroughly protective, 
and is very distinctly marked throughout the genus by the dark 
crescent on the breast and the dark colour of the under surface of 
the wings. Though pronounced and apparently peculiar to the 
Sand-Grouse, a similar pattern is found in some of the Pigeons, as 
well as in the Plovers and in Grouse. 
The nestling plumage of the Sand-Grouse consists of a thick downy 
cover with fine terminal hairs to each down-feather, much like that 
of the Plovers and Fowls, whilst the Pigeons, when hatched, are 
almost nude and are entirely devoid of downy feathers. 
The oil-gland is present and quite naked in Sand-Grouse and 
Pigeons (in some Pigeons wanting), whilst in the Gallinacei and 
Limicole this organ is tufted. 
In both form and structure the “tarsus”? and the claws of the 
Sand-Grouse closely resemble those of the Gallinacei, but are re- 
markable for the tendency to suppression of the first or hind toe, 
which in Syrrhaptes is entirely aborted. This never occurs amongst 
the Pigeons and Fowls, but is a common feature in the Pluvialine 
tribe. 
The dell and the nostrils of Pterocles are like the same parts in the 
Turnicide, which, like Pterocles and the Columbe, are schizorhinal, 
whilst the Rasores proper are what Garrod termed holorhinal. 
OsTEOLOGY. 
Asthe osteology of Péeroclesand Syrrhaptes has been fully described 
by Professors Parker and Garrod, it will be superfluous for me to do 
more than indicate some of the salient points. Prof. Parker says :— 
«There is no vomer inthe Syrrhaptes to tie the two palatines together; 
and this is a sudden assumption of a columbaceous character.” 
However, this is not of great importance, because most of the Tetra- 
onidze have also no vomer, or at least this bone is very much 
suppressed. 
The skull certainly bears many striking affinities to the Columbee. 
The Syrrhaptes keeps close to the Fowls in respect of its vertebral 
characters. 
Number of 
cervical vertebree. Dorsal. Sacral. Caudal. 
Syrrhaptes........ 16 4 15 6 
Pterocles arenarius. . 15 5 15 7 
Columba livia...... 14 4 14 7 
Gallus*’.. 2.0.0... 16 4 15 6 
“There is much that is Pigeon-like in the pelvis of the Grouse 
and the Syrrhaptes.”’ 
All the wing-bones, and in particular the humerus, strikingly 
resemble those of the Pigeons (see Garrod, P. Z. S. 1874, p. 255, 
fig. 1). 
Muscutar Syste. 
I myself have examined specially only the muscles of the 
pelvic region and those of the hinder extremity. As regards the 
* Parker, /. c. 
