BIRDS OF NORTH AND MIDDLE AMERICA. 35 



Nidification. — Nest open above, more or less bulky, placed in low 

 trees, in bushes, or on or near ground, composed ol shreds of bark, 

 dead leaves, dry grasses, etc., lined with finer shreds of bark, fine 

 rootlets, etc., that of H. mustelina with a plastering of mud between 

 lining and exterior; eggs (2-5) greenish blue, with or without brown 

 spots. 



Range. — Confined to the Nearctic Region" (one species extending 

 its breeding range to eastern Siberia) ; south in winter to Cuba, 

 Mexico, Central America, and South America. (Five species, with 

 additional subspecies.) 



Although usually considered as closely allied to Turdus, the rela- 

 tionships of this group seem to be decidedly with Catharus, an 

 opinion first formed by careful examination of their structure and 

 later confirmed by observation of four species of Catharus in life, the 

 habits and songs of the Cathari (especially C. frantzii and C gracili- 

 rostris) being strikingly similar to those of the HylocicMx. 



KEY TO THE SPECIES AND SUBSPECIES OF HYLOCICHLA. 



a. Bill larger and stouter, the exposed culmen more than half as long as tarsus; tail 

 relatively shorter, less than distance from bend of wing to end of secondaries; out- 

 stretched feet reaching nearly, if not quite, to tip of tail; sides and flanks sjjotted; 

 pileum more rufescent than back. (Eastern temperate North America, south in 

 winter to Cuba, Jamaica, Porto Rico, and Nicaragua.) Hylocichla mustelina (p. 37) 

 aa. Bill smaller and more slender, the exposed culmen less than half as long as tarsus; 

 tail relatively longer, equal to or longer than distance from bend of wing to end 

 of secondaries; outstretched feet falling far short of tip of tail; sides and flanks 

 not spotted; pileum concolor with back. 

 b. Outermost (spurious) primary equal to or longer than primary coverts; ninth 

 primary shorter than sixth; tail and upper tail-coverts distinctly more rufes- 

 cent than color of back. {Hylocichla guttata.) 

 c. Sides and flanks grayish or olivaceous; bill relatively smaller or more slender; 

 tail relatively longer; feet relatively smaller. (Western subspecies.) 

 d. Smaller (wing averaging less than 90). 



e. Wing averaging more than 86 in male, more than 84 in female; coloration 



darker and browner. 



/. Coloration lighter, the back, etc. , more olive, the chest more faintly tinged 



with buff, the sides and flanks more gray. (Breeding in coast district 



of Alaska, from Lynn Canal and north side of Cross Sound to Kadiak 



Island, Alaska peninsula, and Nushagak; in winter south to Lower 



California, Mexico, and Texas.) Hylocichla guttata guttata (p. 39) 



ff. Coloration darker, the back, etc., more sepia or'olive-brown, chest more 

 deeply buffy, sides and flanks more olive. (Breeding in coast district 

 of southern Alaska and British Columbia; south in winter to Cali- 

 fornia and Arizona.) Hylocichla guttata nana (p. 42) 



a The Palsearctic Turdus musicus has been referred to Hylocichla by some authors, 

 a view of its relationship which I at one time shared; but more recent and careful 

 study has convinced me that it is much more nearly related to Turdus (an exclusively 

 Old World type) and perhaps not separable from that genus. Among the characters 

 which clearly exclude it from Hylocichla are the extremely minute spurious primary, 

 relatively longer wing and middle toe and shorter tarsus (wing much more than three 

 and a half times as long as tarsus, and middle toe, without claw, more than three-fifths 

 as long as tarsus) . 



