440 SYSTEM A TIC SYNOPSIS. — PA SSEBES — CLAM A TORES. 



well-turned brim, of fine fibres stuck over with lichens, the whole looking much like a nat- 

 ural excrescence of the tree. Eggs 4-5, creamy-white, marked with reddish-brown and 

 lUac in various pattern, usually wreathing and blending about the larger end, sparser else- 

 where; size about 0.75 X 0.65 — pe-a-wee ! d-pee-wee' ! 

 383. C. V. ricli'ardsoni. (To Sir John Kichardson.) Western Wood Pewee. Similar; darker, 

 more fuscous-olive above, the shading of the sides reaching almost uninterruptedly across the 

 breast ; belly rather whitish than yellowish ; outer primary usually not obviously white-edged ; 

 bill below oftener dusky than yellow, sometimes quite black. I fail to appreciate any reliable 

 differences in size or shape ; or, in fact, any specific character. It is impracticable to pronounce 

 upon a pewee, in the closet, without knowing the locality ; but those familiar with lioth Eastern 

 and Western birds in field, agree that thoy are not exactly the same. Note not exactly like that 

 of virens; nesting said to be difierent {Aucluhon, Allen). Rocky Mountains to the Pacific; 

 "Labrador" {Audubon). (Tyrammla richardsonii Sw., Fn. Bor.-Am., ii, 1831, p. 146? 

 Contopus richardsonii Bd., B. N. Am., 1858, p. 189 ; Muscicapa phcebe Aud., B. Am., 8vo. ed., 

 i, 1840, p. 219, pi. 61 ; Nutt., Man. i, 2d ed., 1840, p. 319. See Coues, B. N. W., 1874, 

 p. 247.) 

 123. EMPIDCNAX. (Gr. e/imV, gcu. i^Triho<:, empis, empidos, a gnat; ava$, anax, king. Fig. 280, d.) 

 The Little Olivaceous Flycatchers. Small olivaceous species, 5.00-6.00 (rarely 6.25) 

 long ; wing 3.12 or less; tail 2.75 or less; whole foot at least id as long as wing ; tarsus more 

 or less obviously longer than middle toe and claw, nmch longer than bill ; 2d, 3d and 4th quiUs 

 entering into point of wing, 1st shorter or not obviously longer than 5th ; tail not over i an inch 

 shorter than wings ; breast not buffy. (Compare Sayiornis, Contopus, Mitrephanes.) As in 

 allied genera, several outer primaries are slightly emarginate on the inner web, but this character 

 is obscure, often inappreciable, and may be disregarded. The coronal feathers are lengthened 

 and erectile, but scarcely form a true crest. There are never any more conspicuous color-marks 

 than in Sayiornis fusca or Contopus virens. The bill varies with the species in size aud 

 shape, from almost as broad and flat as in a wood pewee in acadicus, to the narrower shape of 

 a pewit in obscurus; but it is always much shorter than the tarsus. It should not be difficult 

 to recognize Empidonax as different from Contopus, due attention being given to the nice points 

 of diagnosis ; but it is a very difficult matter to discrhninate the numerous species, requiring 

 much tact, care, and patience. The following account, carefully prepared after examination of 

 a great amount of material from all parts of the country, will probably suffice to determine 

 ninety out of a hundred specimens ; but I confess it does Jiot entirely satisfy me ; and, as it does 

 not fuUy answer all the requirements of the case, it must be regarded as provisional. How 

 much alike are these interesting little birds may be inferred ft-om the fact that Wilson knew 

 but a single species, acadicus, to which Audubon added but one, trailli, until Baird showed him 

 two more, minimus and flaviventris. Yet these four are perfectly distinct birds. Any experienced 

 collector knows them to be different, not only when he has them in hand, but in life, by their 

 haunts and habits, their notes, nests and eggs — indeed, the nests and eggs of each of them are 

 readily discriminated. Three oi them are common New England breeders — trailli, minimus, 

 and flaviventris; while acadicus is the common breeder in the Middle States. The case is 

 complicated, however, in the West. The two exclusively Western species, hammondi and 

 obscurus, are pretty distinct — entirely so from each other; but the recognition of "^ji<si7Z«<s'' 

 and especially " difficilis " is somewhat conventional. Since 1858, when Baird first fixed the 

 species upon anything like a satisfactory footing, no changes whatever of his determinations 

 and characterizations have been established ; and as it is useless to exchange one doubtful 

 opinion for another, the less ob\nous species may be suffered to remain as he left them. It is 

 not reasonably possible to analyze all the fonns in concise phrase ; the student must go at once 

 to the detailed descriptions ; but the following may help him somewhat : — 



