SAND-GROUSE. 235 



and allowed to run with barnyard fowls. Tiicy go in considerable flocks ; their nests 

 are large and rather clinnsy affairs, built of sticks, leaves, and grass; the eggs are white 

 and rather large ; and the birds themselves are much sought after for the table, as 

 their flesh is delicate and j)alatable, similar to that of the turkey. With this group 

 the list of the species properly considered as belonging to the order GaJlinaj ends. 

 The species, as will have been observed, are vo-y numerous and of great varietv, and 

 form one of the most — if not, indeed, the most — important group of birds in the 

 entire range of ornithology. 



ORDER XIII. — PTEROCLETES. 



The sand-gronse, which form this order, have usually been included by naturalists 

 in the order Gallina?, but the obvious imjiropriety of this has at length been eoiieeded, 

 and they are now elevated to a distinct order, lying between the Alectoromorjilia; on 

 the one hand and the Peristeromorphaj on the other. Tbej' resemble the first of these 

 great grouj)S in their skull, palatines, maxillo-palatines, and bill ; and the second in 

 their pterygoid and basipterygoid ])rocesscs, sternum, furcula, coracoid, and fore- 

 limbs. The feet, with its short hallux, entirely wanting in Sjjrrhaptes, and the short 

 tarso-metatarsus, are very unlike a jiigeon's. The vocal organs are pigeon-like; the 

 trachea is cartilaginous, with a ]iair of laryngeal muscles at its bifurcation; but the 

 crop, gizzard, gall-bladder, ami small intestines arc like those of Gallinaceous birds. 

 The cceca coli are voluminous, ami have twelve continuous longitudinal folds in their 

 mucous membrane. The pterylosis differs somewhat from that of the jiigeon. The 

 lateral neck-spaces reach only to the beginning of the neck ; the su]ierior wiug-si)ace 

 is absent; the lumbar tracts coalesce with the posterior part of the dorsal tract, and 

 the latter joins the plumage of the tibia. The sand-grouse jiossess an after-shaft on 

 the contour feathers, thus differing from the i)igeons, and, unlike the Gallinaceous 

 birds, have a naked oil-gland. In some characters these birds are plover-like, but they 

 drink like a pigeon, thrusting the bill uj) to the nostril into the water, and retaining it 

 there until the thirst is satisfied. 



The family Pteroclid-k is composed of two gener.a, Pterocles and Si/rrhiiptes, the 

 species of which resemble each other in their general shajie, having a rather he.avy 

 body, long, pointed wings, and extremely short legs and toes. They are awkward 

 birds upon the ground, l>ut move rapi<lly and gracefidly on the wing. Pterocles has 

 the tarsi feathered in front, and in !Si/rfhaptes both tarsi and toes are completely 

 covered with feathers. In the osteology of these genera considerable differences are 

 observable. The skull oi Si/vrhdptes is more ]iigeon-like th.m Pferocks ; the upper 

 frontal region is narrower between the eyes, and the ahv of the ethmoid are less 

 swollen between the crura of the nasal. In Pterocles the bones of the face are strong 

 like a j)igcon's; the lower jaw bends farther back; the jiostorbital and squamosal 

 processes and the malar arch are also stronger. The scapula is grouse-like, and there 

 is one more caudal vertebra than in iSi/rrhaptes, and tlie styliform and sacral ribs 

 have no appendage, but both genera h.avc a rmliment attached to the last ha;niapo- 

 physis. The sternum of Pterocles has the ej)isternum and hyosternal ))roccsses as in 

 S)jrrhaptes ; but the external hyposternal |>rocesses are shorter. The species of sand- 

 gi'ouse are inhabitants of Asia, India, and Africa, especially of the last continent, 

 ■where twelve of the sixteen or eighteen recognized s])ecies arc found. J'Icrocles 

 comprises the great majority of known forms, Syrrhaptcs having only two sj)ecie8. 



