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Show 348 brighter- colored than its southern ally, the red being not only deeper and more extended, but the brown of the body is darker and richer! The fact that littoralis has more gray on the head than tephro-cotis cannot be explained by stating that the former is more northern in its distribution, for such is not the case, since the breeding grounds of var. tephrocotis are quite as far northward in the interior as those of var. littoralis is on the coast. We must, therefore, look to some other explanations of these variations than the laws of climatic modifications which are now recognized. The single instance of apparent correspondence to a general rule of geographical variation is seen in L. griseinucha of the Alaskan coast, which is more northern in its habitat than L. littoralis of the more southern North- Pacific coast, and is also larger in size.*- ( Loc. cit, pp. 58, 59.) From much of the above I must beg leave to dissent, as matters of fact. In the first place, L. australis was one of the forms to which I especially referred, and which, because it has since been considered by him as a species rather than a variety, Mr. Ridgway leaves wholly oat of consideration in this connection. It is, however, one of the " forms of Leucosticle" to be considered, and is also the most southern, the smallest, and by far the brightest- colored.* Climatologically considered, I. tephrocotis is the next most southern,! is the next in size ( at least is not larger than variety littoralis), and has the least ash on the head. The breeding- range of L. littoralis is not known, and this fofm has not yet been taken on the " southern part of the North- Pacific coast", unless Alaska can be so considered. In size, it does not appreciably differ from L. tephrocotis. It probably passes the summer in the interior, to the westward of the breeding- range of L. tephrocotis, and hence under rather more northern climatic conditions. L. griseinucha is the most northern and much the largest Its darker colors are easily explainable on climatic grounds, or by " the laws of climatic modification which are now recognized ". . Its darker colors simply correlate with those of the generality of the varietal forms of Birds and Mammals inhabiting the same region, remarkable for its immense annual rain- fall and great humidity of • X. " atrata " I have purposely omitted in this consideration. If, however, it is anything more than a melanotic phase of variety tephrocotis, it finds in that form a very near ally, and if entitled to specific, or even varietal, recognition, gives farther proof of the generalization here proposed, it being much darker and smaller than tephrocotis. Mr. Ridgway says of atrata, " the pattern of coloration is precisely similar to that of JL tephrocotis, hat the totally different tints ( black or dusky- slate, instead of chocolate-brown), and the very marked difference between th% sexes* separate it at once as a distinct species. It may be suggested that it is a melanism of tephrocotis; bat, if this were so, there wonld be no such entire uniformity of characters as is exhibited throughout the series of five specimens, while in tephrocotis there is not Vie slightest sexual difference in colors."* It will be noticed from the above that one of the strong poiuts relied upon by Mr. Ridgway as distinguishing atrata from tephrocotis is the supposed absence of sexual variation in tephrocotis, and its presence in atrata, a distinction founded on error. t In this view I find I am sustained by Mr. C. E. Aiken, who says," From these tacts, and information derived from other sources, I infer that the gray- cheeked variety { littoralis) is the most northern race, and that many of them do not find their way so far south [ as Cafion City, Colo. 1 except in severe winters. In this belief I am strengthened by the fact that, of sixty birds killed in Wyoming in 1870, all but one or two were typical tephrocotis; that tephrocotis occupies, during the breeding season a more southern locality than the preceding [ littoralis'], and wibters, regularly, in the Rocky Mount ains of Colorado, and even farther south; that australis inhabits the next lower section, breeding in Colorado, and probably extending into the British possessions, but wintering, for^ the most part- especially in severe winters- south of this Territory: that atrata, if anywhere common, must occupy a more southern locality."-{ Quoted from Mr. Ridgway- 8 Mon., I. c, pp. 62,63.) * Not Italicized in the original. |