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174 THR CONDOR Vol. XV the male of arcticus the.black of the upper parts is usually more mixed with olivaceous or grayish, and the white markings, especially of the scapulars and rectrices, are rather more extensive and noticeable, but these differences are not especially conspicuous, and at a casual glance the males of the two forms look very much alike. There are no differences of moment in size or proportions. The females of the forms are so dissimilar, however, as to leave no doubt as to the distinctness of the two. In curtatus the female i? of the type of th'e western races of P. maculatus in ffeneral, with the head and the ground color of the upper parts very dark (a dull slate color), with little or no indication of brown. In the female of arcticus these same areas are so overlaid with a browu- ish suffusion as to give a decidedly different and lighter tone of color to the whole bird. This is not a difference requiring close scrutiny for discernment, but is something that is readily apparent at a glance. When series of females of P.m. curtatus, P.m. arcticus, and P. erythrophthahnux are laid out side by side, so as to produce a general "mass effect" of each of the three, the body color of arcticus appears to be almost intermediate between the slaty hue of curtatus and the brown of erythrophthalmus. Thus the study of this material leads directly to the conclusion that the name curtatus should not be considered a synonym of arcticus, as has been claimed, but that it represents a distinguishable subspecies, apparently inter- mediate between the paler colored Rocky Mountain forms and the more intense- ly black Pacific Coast races. The material available in the present study shows unbroken intergradation from curtatus through [alcinelIus to the extremely dark megalonyx, though not between curtatus and arcticus. In this connection the probability suggests itself of the breeding bird of the central Rocky' Mountain region (Utah, Colorado, etc.) being of the form cur- tatus rather than montam?s, to which it is at present referred, but the pertinent tnaterial at hand does not warrant more than the suggestion. In differentiating curtatus from the other California forms the pale color of the chestnut areas in the former appears to be an excellent character. A molting bird at hand from the Warner Mountains (Mus. Vert. Zool., no. I486I ), in which many of the chestnut-colored side and flank feathers are still partly en- sheathed, nevertheless has these parts lighter colored than examples of [alci- nellus or megalonyx. The absolutely fresh and unworn condition of the feathers in this case is conclusive evidence against the assumption that the paler color of curtatus is due to fading, being produced by the fiercer heat and sunshine to which it is exposed. LITERATURE CITED AMERICAN ORNITHOLOGISTS' UNION COMMITTEE, J. A. ALLEN, CHAIRMAN AND EDITOR. 1910. Check-List of North American birds. Ed. 3, revised (New York, American Ornithologists' Union), 430 pp., 2 maps. 1912. Sixteenth supplement to the American Ornithologists' Union check-list of North American birds. Auk, 29, pp. 380-387. GO?,DMAN, E. A.' 1908. Summer birds of the Tulare Lake region. Condor, 10, pp. 200-205. 1902. Check-list of California birds. Pacific Coast Avifauna, 8, pp. 1-98, 2 pls. (maps). 1911. Description of a new spotted towhee from the Great Basin. Unix,. Calif. Publ. Zool., ?, pp. 309-311. LINTON, C. B. 1908. Pipilo clementae excluded from Santa Cruz Island avifauna. Condor, ?0, p. 208. 1909. Further notes from San Clemente Island. Condor, ?, pp. 193-194. RII)GWA, R. 1899. New species, etc., of American birds.--IV. Fringillidae (concluded); Corvidae (part). Auk, ?6, pp. 254-256. 1901. The birds of North and Middle America. U.S. Nation. Mus. Bull., 50, part 1, xxxq-715 pp., 20 pls. 1906. "Atratus versus megalonyx." Condor, 8, p. 100. SWARTH, H. S. 1905. Atratus versus megalonyx. Condor, ?, pp. 171-174, 1 fig. (map).