NATURAL SCIENCES OF PHILADELPHIA. 88 



Still a fourth series is recognizable in the collections before me, embracing 

 examples from New Mexico and Arizona; collected by myself near Fort Win- 

 gate, in New Mexico, and by J. H. Clarke on the Gila River. These exhibit a 

 remarkable gradation towards the peculiar features of psaltria. The black of 

 the back is mixed with about an equal amount of olive, the proportions of the 

 two colors varying from e. g. No. 37088, where there is only a trace of olive, 

 to e, g. Nos. 37091 2, where there is decidedly more olive than black, so 

 much indeed that this color forms quite a contrast with the black pileum. The 

 auriculars are black as in mexicanus, but, the yellow lower eyelid, like that of 

 psaltria, is not disconnected with the yellow of the throat. All three of these 

 birds i shot out of the same flock at the same time, (June 28, 1864.) The Gil* 

 birds agree exactly with the most olivaceous of these just described. A spe- 

 cimen No. 39094, tf, Aug. 18, Fort Whipple,) of supposed psaltria with a pure 

 olive back, has the auriculars black. 



From the above detailed features of large series of skins, representing lo- 

 calities all the way from Panama to Northern Arizona, it will be evident that 

 the typical style of mcxicanus from the table lands merges, by insensible degrees, 

 through Costa Rican examples into an extreme of form which has been desig- 

 nated as C. columbianus. In like manner, just north of Mexico where the con-, 

 fines of the species inosculate with those of psaltria, we have a race or form- 

 showing decided gradations towards the characters of the Sa-t named species . . 

 But still the typical psaltria is so very diverse from mexkanus proper, and the 

 doubtful specimens incline po very decidedly towards the latter, that, in the 

 impossibility of uniting psaltria with mexieanus, we must consider them as " va-- 

 rieties" of the latter, unless, indeed, they be hybrids between the two.* 



Upon the whole, then, it may be best to refer all the black-backed examples. 

 to one species, mexkanus, recognizing three " varieties;" columbianus, mex* 

 icanus and arizonsc, as at least a convenient mode of indicating the differences, 

 whatever be their value, which actually do exist. 



Regarding the females of the two species and of the varieties, \ confess my 

 inability to distinguish them with tiny degree of certainty, except by the lo- 

 calities whence they come, since all are quite similarly colored, and tut re are 

 no very tangible differences of form. 



140. Chrysomitris Lawrencei (Cassin ) Bonap. 



Abundant.; probably resident. My numerous examples of this species, so 

 widely dissimilar from any other, were all taken at Fort Whipple in winter. 

 Although I never noticed it at any other season, I have little doubt that it is a 

 permanent resident, breeding in the mountain* of Northern Arizona. I nave 

 seen summer examples from Fort Tejou, Cal. The differences between winter 

 and spring or summer specimens, consists in little else than the replacing of 

 theyellow dorsal spot by olive~gray, either pure or a little mixed with yellowish. 

 The yellow of the other parts is as bright as in spring, and the black frontlet 

 remains intact. Females want entirely the black on the head, which is all 

 around plain olive gray, while the pectoral spot and other yellow parts are dulli 

 in tint, and restricted in extent, or even, as may be the case sometimes with 

 the dorsal s<pot, entirely wanting. The iris of both sexes is dark brown. Iq 

 summer the bill and legs are fledi colored, more or less obscured bv 

 dusky; in winter the bill is hotn blue, and the legs, feet and claws blackish 

 liruwn. 



The species has been hitherto considered as chiefly a California Coast bird. 



141. Chrysomitris pinds (Wils.) Bp. 



A generally distributed species, undoubtedly to be hereafter added to the 

 Whipple list. ' Fort Thorn, N. M , Dr. T. C. Henry, U. S. A. 



*"How convenient it would be if we could, with dignified imperturbability, accept a broad theory 

 of hybridization as the correct solution of these constantly recurring atd vexatious problems !" 



1866.] 



