204 MR. W. K. PARKER ON THE OSTEOLOGY 



The foot of the Syrrhaptes reminds me of that of the Hyrax ; but the latter creature, 

 having two pairs of limbs, takes advantage (not being able to burrow) of ready-made 

 houses in the clefts of the rocks ; the home of the Syrrhaptes is on the vast sandy 

 plateaux of Central Asia. For a description of these " Steppes," see Humboldt's 'Views 

 of Nature,' Bohn's edit. pp. 3, 28, 57. This gentle desert-bird has great charms for me, 

 and it would be much more appropriate to write a sonnet in its praise than to spend 

 all this time and labour in a dry and positive description of its osteology. 



The viscera of the Syrrhaptes are tetraonine to a great extent ; the trachea is carti- 

 laginous, and it has at its bifurcation what the Grouse is bereft of, viz. a pair of laryn- 

 geal muscles, as in the Pigeon, Talegalla, and Plover. 



The crop, gizzard, gall-bladder, and small intestines are much the same as in 

 ordinary Gallinaceous birds ; but, as in Lagopus, the caeca coli are very voluminous, 

 they have, however, twelve longitudinal continuous folds in their mucous membrane, 

 not seven as in the Ptarmigan. The proventricular glands are ovoidal and simple, as 

 in the Pigeon and Plover, not botyroidal as in the Grouse and Fowls. In the latter, 

 e. g. Pavo, Meleagris, Numida, Phasianus, Dendrortyx, the caeca coli are not so long, 

 and have inosculating folds. 



Example 2 : The Common Sandgrouse {Pterocles arenarius). 



The difference between the skull of Pterocles arenarius and Syrrhaptes paradoxus are 

 not great, but they are important. The head and face of the former are altogether 

 stronger, more gallinaceous, and less pigeon-like than in the latter. The skull-base 

 has, in the Pterocles, that peculiar breadth which arises from the struthiousness of its 

 structure. The upper frontal region is broader between the eyes, and the alse of the 

 ethmoid swell up to a greater extent between the crura of the nasal. The postorbital 

 and squamosal processes are much stronger, and make a thicker bridge over the tem- 

 poral fossa. The crossing of the posterior and horizontal semicircular canals project 

 in the same hemispherical manner as in Syrrhaptes, and the tympanic ala of the lateral 

 occipital is equally arrested. The malar arch is stronger, and the central interorbital 

 space is filled up ; so also are the orbito-frontal fontanelles ; the common optic foramen 

 is more closely and neatly circumscribed. There is still an oval slit, opening into both 

 orbits, between the ethmoid bar and the lower edge of the frontals at their coalescence. 

 The antorbi to-lachrymal mass is equally large, and the septum nasi as well developed 

 and as completely ossified. The bones of the face generally are quite as strong as in 

 ordinary Pigeons, and therefore a degree beyond wiiat is seen in Syrrhaptes. The 

 double head of the " os quadratum " agrees with the same structure in Syrrhaptes ; and 

 there is nothing special to remark upon in the bones of the palatine region. The lower 

 jaw is altogether stronger and deeper, its bend is more marked and further back, than 

 in that of Syrrhaptes ; the membranous space is of about the same size, as are also the 

 angular processes. 



