PASSERES — MERULID.E — MERULA. 73 



THE OLIVE-BACKED THRUSH. 



Merula olivacea. 



Tardus olivaceut. Giraud, Birds of Long island, p. 91. 



Characteristics. Uniform yellowish brown above. Breast and throat buff, with small 

 sagittate black spots : outer webs of the primaries yellowish ; lower 

 tail-coverts white. Length, 7 inches. 



Description. Second quill-feather longest ; the first and third equal. Tarsi one inch 

 long. Bill short and robust. 



Color. Uniform dark olive brown above. Sides of the neck, circle round the eye, and a 

 line from the bill to the eye, rufous. Throat cream-color, inclining to rufous ; fore part of 

 the throat with arrow-headed spots, smaller and more distinct than in M. solitaria. Sides 

 light greyish brown : under tail-coverts pure white ; abdomen white, spotted with light 

 greyish brown. Bill dark brown, approaching black. 



Length, 7'0. 



For the first detection of this species, we are indebted to the late H. C. De Rham of this 

 city, a young man of singular attainments and great zeal in the investigation of our ornitho- 

 logy. He died in consequence of fatigue and exposure to the sun in Carolina, while in the 

 pursuit of his favorite studies. He furnished me with the following note, which I believe 

 was subsequently read before the Lyceum of Natural History : 



" Having been struck by the difference between the figures of the Hermit Thrush as 

 given by Wilson and Audubon, I was led to examine numerous specimens, and observed 

 very remarkable discrepancies, such as induced me to suspect the existence of two distinct 

 species. One, agreeing with Audubon's figure and the descriptions of Bonaparte and Nuttall, 

 being yellowish brown above, inclining to rufous on the tail-coverts and tail, the outer webs 

 of the primaries being of the same color ; the other agreeing with Wilson's figure, the whole 

 upper parts being of a yellowish brown, rather lighter than in the thrush figured by Audubon, 

 without the rufous tail, and the outer webs of the primaries inclinirfg to yellowish instead of 

 rufous. The description of Wilson is so vague, that it may apply to either. The relative 

 length of the folded wing, and of the primaries, is also very striking. In Wilson's, the 

 wings reach to within an inch of the tail ; those of Audubon to within an inch and a half. 

 In Wilson's, the third is longest, the second and fourth equal ; in that described by Audubon, 

 the fourth longest, the ihird and fourth subequal. Mr. Audubon cites the minor of Rich- 

 ardson merely as a synonime of wilsoni, while Bonaparte notes it as a distinct species. I do 

 not undertake to say whether two species have been confounded under one name, but it is 

 certainly singular that such marked differences should occur in birds shot at the same season 

 of the year." 



I had been previously struck with great discrepancies between many specimens which 

 [Fauna — Part 2. J 10 



