OF NORTHERN ILLINOIS. 



515 



The genus Passereuhis affords another eminent example of the doubtful nature of species, 

 if we allow the five described in the General Report on North American Birds to be distinct. 

 On the other hand, if we refer all to P. savanna, we have one positive species, with at the 

 same time a range and a character of variation not at all unusual ; the differences in size 

 between some of the supposed species being just such as we should expect in the different 

 localities from which the specimens come in any species with the same range of latitude. 

 So in Cyanwra, of which we have one species, the C. cristata Swain., in the eastern half of the 

 United States, presenting considerable variations in depth of color, and in the size and shape 

 of the bill and crest, and in the western half its congeneric representative, C. Stelkri Swain., 

 with strictly analogous variations, but on which ornithologists have based several so-called 

 species, (as 0. coronata Swain., C. macrolophus Bd., etc.), all so closely allied that we find their 

 authors expressing grave doubts of their validity. The genus JEgiothus gives us another 

 example of seven closely allied species, according to a recent authority, 1 while still others 

 have been indicated by Brehm, where even two cannot be positively defined, and all 

 should probably be referred to one ; the variations in size agreeing with the common vari- 

 ations in other species according to latitude, and those of color, shape of the bill, etc., with 

 numerous parallel cases in undoubted species of Sylvicolidce. It is a source of surprise to me 

 that ornithologists contend persistently for the existence of species where the characters on 

 which they are based are so slight that in repeated instances they admit the distinction to 



Merula minor Swainson, Faun. Bor. Am., II, 1831, 179, 



PI. 36. 

 Turdus ustulahts Nuttall, Man. Am. Orn., I, (2d ed.), 

 1840, 400. 

 " " Baird, Birds N. Am., 215; ib. Rev. Am. 



Bds., Pt. I, 1864, 18. 



Sp. Ch. — Above nearly uniform reddish brown. Below 

 white; sides pale ashy brown; neck in front and breast pale 

 yellowish brown, but. very variable in intensity in specimens 

 collected at the same locality and season, as is also the color 

 above; breast and fore neck with small triangular or sublinear 

 spots, generally like the back, but sometimes decidedly darker. 

 Sometimes they are very conspicuous, equalling in size oc- 

 casional extreme specimens of T. Swainsoni, and again are 

 nearly obsolete. Specimens with these larger and well de- 

 fined spots accord with what authors call T. uslulatus. Differs 

 from T. Swainsoni through a general difference in color, espe- 

 cially of the upper parts, and in the character of the markings 

 below. Also from T. Pallasi in this last respect, and also in 

 the uniformity in the color of the upper parts. 



The three species above characterized have in coloration no 

 single general character in common. Two (T. Pallasi and 

 T. Swainsoni) agree occasionally quite nearly in that of the 

 ventral aspect, but a glance at the dorsal suffices to separate 

 them. Two (T. Swainsoni and T. fuscescens), also agree in 

 the uniformity of the color above, but it generally differs widely 

 in tint, while a glance at the ventral surface suffices at once to 

 distinguish them. Each has a considerable range of color vari- 

 ation, regardless of sex, season, or locality; it is, however, to a 

 greater or less degree, unmistakably connected with age. 



1 Dr. Elliot Coues, Monograph of the Genus JEijiothus, 

 Proe. Acad. Nat. Sc, Philadelphia, Nov. 1861. In justice to Dr. 

 Coues I should add, that, after the examination of more mate- 



rial received at the Smithsonian Institution, in some Additional 

 Remarks on the North American JEgiothi, (same Proc, Feb. 

 1863), his doubts of the validity of two species, JE. rufescens 

 and JE. HolbSUi, had become considerably strengthened. In 

 this connection he mentions a highly suggestive series of skins 

 collected in winter in the vicinity of Quebec. " Selecting from 

 the series two or three skins which differ most markedly from 

 the usual style of linarius, and comparing with typical speci- 

 mens from Philadelphia," he found a marked difference in 

 size, while, save slight differences in the color of the bill and 

 throat, the birds were otherwise " quite identical." " But now, 

 on examining in detail, the rest of the series," he continues, " I 

 find that, from the one extreme, the characters of which have 

 just been given, there is a complete and gradual transition — a 

 diminution in size, down to specimens which cannot possibly 

 be distinguished from typical linarius. There is no break in 

 the series, no dividing point where we can stop calling the 

 specimens 'linarius' to give them another name, in spite of 

 the discrepancy so evident between the two extremes." 



Several winters since JEgiothus linarius was excessively 

 abundant at Springfield (Mass.) for two months, during which 

 time I killed and examined great numbers of specimens, and 

 in which I noticed considerable variations in size, as well as in 

 the depth of color of the general plumage, specimens varying 

 from light to dark tints, with varying amounts of rufous, 

 besides the common variations in the rosaceous and carmine 

 tints, without being able to satisfy myself that the immense 

 flocks sweeping about over the fields or unsuspiciously feeding, 

 embraced more than one species, though I was searching among 

 them for a second. They remained till April, and before 

 they left, the rosaceous tints in the males had markedly 

 increased. 



