OF NORTHERN ILLINOIS. 



509 



which his description leads one to expect. The specimen is of the ferruginous type of 

 T. Swainsoni, having this tint rather unusually intense throughout, both above and below. 

 It has, moreover, each feather of the outer row of coverts, and two or three of the 

 inner secondaries tipped with a conspicuous drop-shaped spot of pale rufous, the tips of 

 the coverts thus forming a light band across the wing, a condition often seen in this genus, 

 in birds of the year. (The specimen was collected October 9, 1867.) 



Another specimen of this species (T. Swainsoni), worthy of notice in this connection, was 

 collected in Newton (Mass.), by Mr. C. J. Maynard, May 25, of the present year. In size it 

 nearly corresponds with the one referred to above, being fully as small, and like it bearing 

 traces of immaturity, in the small drop-shaped spots of pale rufous tipping the greater wing- 

 coverts. The base of the lower mandible is also more decidedly yellow than in average 

 specimens, a color which is exceedingly variable in all our Thrushes, though perhaps most 

 notably so in the Robin (T. migratorius). In color, especially the color of the bill, it accords 

 with Audubon's figures of I 7 , nanus in his Birds of America (fig. 147); but does not at all 

 agree, except in size, with his description of the same. In general color it is very much paler 

 than Mr. Thaxter's specimen. Another specimen before me, collected near the same time and 

 place by Mr. Maynard, is so much larger, that if the birds came from localities a thousand 

 miles apart, few ornithologists would fail to consider them specifically distinct ; but in reality 

 a connecting series from nearly the same locality fully substantiates their identity. We ap- 

 pend the measurements of the three specimens in question, remarking that there is also quite 

 as much difference in color as in size; but the two nearest alike in measurements differ most 

 in color! The first was taken in October, and the others in May, and all within five miles 

 ■of the same point. 



As has been observed, both the smaller specimens are undoubtedly young birds, of prob- 

 ably less than a full year. The length and alar expanse were taken from the specimens 

 when fresh, by the collector; the others from the skin; the length of the culmen is the 

 measurement given for the bill.] 



4. Turdus PaUasi Cab. Abundant a little earlier in the season. 



Among the specimens of this species in the museum of the Chicago Academy from this 

 county, is one a little darker colored than usual, labelled, I think by Mr. R, Kennicott, 

 '• Turdus silens." During my investigation, four and five years since, of the Swainsoni and 

 Alicke question, I noticed such great and analogical differences in Massachusetts specimens 

 of T.fusccscens and T. PaUasi as led me to believe that T. ustulatus and T. nanus were to these 

 species respectively what T." Alicke" is to T. Swainsoni ; simply individual variations and 

 not distinct species. Further opportunities for investigation in the mean time, with authen- 

 tic specimens of T. nanus and T. ustulatus for comparison, have but fully confirmed these con- 

 victions; and I now as confidently add Merula silens Swain. (Fauna Boreali- Americana, II, 



MEMOIRS HOST. SOC. NAT. HIST. Vol. I, Pt. 4. 



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