WHITE-QUILLED ROCK PIGEON. 255 



of quills margined with whitish, as also the feathers of the fore-neck ; the black 

 throat patch scarcely indicated ; a certain amount of chestnut on the under wing- 

 oo verts like that of the quill-lining. 



Nest. The bare ground, under any convenient low covert tussock or bush 

 on the plains. 



Eggs. Clutch, two ; elliptical in form ; texture of shell fine but strong ; surface 

 glossy ; white, with a slight creamy tone. Dimensions 32-34 mm. by 24. 



Breeding-season. Practically all the year round. 



Distribution and forms. Interior of Australia only. The western form, living 

 in interior districts of the North-west of Australia is much paler above and below, 

 being named H. h. alisteri (Mathews), than the typical eastern H. h. histrionica 

 (Gould) from the interior of New South Wales and Queensland. 



Genus PETROPHASSA. 



Petrophassa Gould, Proc. Zool. Soc. (Lond.), 1840, p. 173, July 1841. Type (by monotypy) : 

 Petrophassa albipennis Gould. 



Large Ground-Doves with slender bills, very rounded wings, long rounded tail 

 and very small legs and feet. The bill is formed as in the preceding genus, the 

 dertrum a little more swollen, the bill itself a little more slender, the interramal 

 bpace less feathered, the gonys a little longer and more ascending but not angulated. 

 There is a small space round the eye and part of the lores naked of feathers as in the 

 preceding genus but more marked. The wing is very rounded, the primaries very 

 narrow, none showing any scalloping on the inner webs but the third to the eighth 

 strongly incised on the outer webs ; the first is not much shorter than the second and 

 is about equal to the ninth, the intervening eight being almost the same length, 

 the eighth being a little less than the others. The secondaries are very long and 

 broad, the longest inner secondary being equal to the outermost primary. The 

 tail is composed of fourteen very broad feathers, their extremities being almost square 

 and is nearly as long as the wing ; in shape it is a broad wedge, the outer feathers 

 being more than half the length of the middle eight which are practically equal in 

 length. The upper tail-coverts are very dense and only reach about half-way down 

 the tail, the under ones being about the same length. The legs are very small ; 

 the tarsus is short and thick, about the length of the culmen, and longer than the 

 middle toe ; the tarsus is covered on the front with two rows of hexagonal plates, 

 the back and sides being covered with minute reticulation. The toes are very 

 short, the middle toe longest, the outer and inner about equal and not a great deal 

 longer than the straight hind-toe ; all the claws are short and blunt. 



Coloration uniform brown or grey with darker edges to all the feathers, forming 

 a scalloped appearance ; primaries showing red or white bases, very noticeable. 



173. Petrophassa albipennis. WHITE-QUILLED ROCK PIGEON. 



Gould, Vol. V., pi. 71 (pt. x.), March 1st, 1843. Mathews, Vol. I., pt. 3, pi. 38, April 29th, 

 191 1. 



Petrophassa albipennis Gould, Proc. Zool. Soc. (Lond.), 1840, p. 173, July 1841 : " Western 

 Australia " = Wyndham, North-west Australia (East). 



Petrophassa albipennis alisteri Mathews, Austral Av. Rec., Vol. I., pt. 2, p. 28, April 2nd, 

 1912 : Napier Broome Bay, North-west Australia (West). 



DISTRIBUTION. North-west Australia, Northern Territory. 



Adult female. General colour of the upper-surface rufous-brown, with pale 

 edges to the feathers ; crown of the head blackish -brown, with whitish margins to 

 the feathers ; neck all round, breast and sides of the face grey, with rufous -brown 

 edges to the feathers ; lores and a narrow line at the base of the fore-head velvety- 



