PERDICID.E: PARTRIDGES AXD QUAILS. 749 



L. ev'ermanni. (To Prof. W. B. Evermaiin. Fig. 502.) Evermann's Rock Ptar- 

 migan. Attu Rock Ptarmigan. Different from any of the foregoing, and bearing upon 

 the Eurasiatic L. mutus rather than upon any of the American forms of L. riipestris. ^ in 

 June blackish, little varied with any russet markings, and these chieHy on the head and neck 

 and rump, leaving the rest uniform except for some lingering white feathers of the winter dress. 

 Forehead, throat, lower breast and belly, crissum, feet, and the whole wings, except some of 

 the coverts, white ; shafts of primaries pale brown. Bill and claws black ; comb scarlet. 

 Lengtli 14.00; wing /.ilO; tail 5.80. 9 in ^^'<^y differs, as usual in this section of the genus, 

 and is smaller; length l.'i.OO; wingG.GO; tail 5.00. Attu Island, about 1,400 miles W. of 

 Unalashka. Elliot, Auk, Jan. 1890, p. 25, pi. 3, pub- in July. A. 0. U. Suppl. Check- 

 List, Auk, Jan. 1897, p. 119, No. 302. 1. (Compare L. ridgwayi, probably to be known as 

 L. mutus ridgwayi, from the Commander Islands, 300 miles W. of Attu.) 

 L,. leucu'rus. (Gr. XeuKos, leucos, white; ovpd, oura, tail. Figs. 503, 504.) Whitk-tailed 

 Ptarmigan. Rocky Mountain Snow Grouse. Mountain Quail. <? 9, in winter: 

 Entirely snow-white; bill black, rather slender, and general proportions nearly as in rupestris, 

 but rather smaller; length 12.00-13.00; wing under 7.00. J* 9 , in summer: Tail, most of 

 the wing, and lower parts from breast, remaining white ; rest of the plumage minutely marked 

 with black, white, and tawny or grayish-brown, varying in precise character almost with every 

 specimen. Rut there is no difficulty in recognizing this white-tailed species, of alpine distribu- 

 tion in western North America extending from Alaska to New Mexico (lat. 37"^), N. to Liard 

 River, W. in British Columbia, Washington, and Oregon. In its southerly latitudes, in sum- 

 mer, it inhabits the mountain ranges from timber-line to the highest peaks, in winter ranging 

 lower down, as it does also in summer in the higher latitudes. Eggs very diflFerent from the 

 heavily painted ones of lagopus and rupestris, and resembling those of the Grouse of the gen- 

 era Canachites and iJendragapus, being of dull creamy complexion, minutely dotted over the 

 whole surface with burnt-sienna, and not thickly enough to obscure the ground-ci)lor, few of 

 the markings exceeding a ])iu's head in size; shape purely ovoidal, greatest diameter near the 

 middle; size 1.70 X 1-14 to 1.85 X 1-20; number variable, usually less than a dozen. In the 

 Rocky Mts. of the U. S. they are laid in June and July. 



Family PERDICID^ : Partridges and Quails. 



Well distinguished fmm Tetraonida; by the nakedness of the feet and nasal fossae; less 

 easily separated from Phftsianidce, which also have tliese parts unfeathered. Viewing only 

 the central or typical members of the Perdicidcc, or ordinary Partridges and Quails, their differ- 

 ence from such birds as Pheasants is obvious; but they are so closely connected by a number 

 of outlying genera that their separation, either as families or as subfamilies, becomes a matter 

 of convention, there being actually no line of demarcation. Thus, in the Indian and Ceyloncse 

 genus Gfdloperdix the characters are equivocal ; both sexes are usually spurre<l, liave the orbits 

 bare, differ in plumage, and are technically phasianiue ; yet they are only 12-14 inches long, 

 with short 14-feathered tail, and have a perdicine aspect. Another equivocal genus is litiinbu- 

 sicolx, with 3 species of India, China, and Formosa, in whicli the sexes are alike in plumage, 

 tlie (J anil sometimes the 9 is spurred, the orbits are feathered, the 14-feathered tail is rather 

 long, and the total length is only 10-12 inches; thus tliey stand directly on the line between 

 jdiasianine and perdicine forms. Again, the African Ptilopachifs fuscus is m>t spurred in either 

 sex; the sexes are alike; there is a jwst-orbital bare space; the moderate tail is 14-feathered; 

 the length is a foot or less, and the whole aspect perdicine. One, the Indian Ophri/sia, is 

 tlioroui^flily (juail-like in aspect, only 8 or 9 inches long, wine 3.50, tail IO-fcatlured. and sexes 

 dissimilar: thus no doubt belonging on thf perdicine siiie of ilie line. The u'cnera hero 



