380 PROCEEDINGS OF THE ACADEMY OP 



great, the species is so marked, and so distinct from any other that there would 

 be no difficulty in recognizing it. The difference in the length of wing of the largest 

 male and smallest female before me is barely three-eighths of an inch. The 

 bill constantly preserves its peculiar size and shape, and in very young birds, 

 still in the downy state, is quite different from that of any other species. The 

 color of the upper parts hardly varies appreciably. The edgings of the wings 

 differ somewhat in breadth, but are never so broad as those of Unarms. The 

 claws vary considerably in acuteness and amount of curvature ; the difference, 

 however, being caused apparently by a greater or less amount of wearing away 

 of the sharp tips. 



Comparison with allied species. The present species, possessing such marked 

 characters, hardly requires comparison with any other except fuscescens. As 

 already stated, it is much larger than that species, the difference in the length 

 'of the wings being nearly half an inch. The next greatest difference is seen 

 in the bills. That of A. fuscescens is larger and everyway stouter than that of 

 Unarms, but the differences between fuscescens and ro stratus in this respect are 

 even greater. As regards color, the two are almost identical, except that in 

 rostratus the dusky streaks of the sides usually extend quite across the lower 

 part of the breast. 



From A. linarius and still more from A. rufescens, the differences are suffi- 

 ciently obvious. It differs iu color exactly as does fuscescens, and, in addi- 

 tion, in the greatly superior size, and the enormously large bill. A. Holbolli 

 has a long and robust bill ; but it is bright yellow, not dusky horn color; and 

 the general colors of the bird are those of linarius. 



In size this -species about equals A. canescens ; but here the resemblance 

 ends. The general very dark, instead of very light colors ; the heavily streaked, 

 instead of immaculate sides; the very large and arched, instead of small and 

 conic bill ; and the very different proportions of tarsus, toes and claws, with 

 other characters, at once separate the two. 



It is unnecessary to institute a comparison with A. exilipes, the characters in 

 almost every particular being exactly opposite. 



Remarks. It seemed to us hardly possible that so very distinct a species as 

 the present could, at this late day, have remained undescribed. We accord- 

 ingly searched with care all the authorities on the subject, which the libraries 

 of the Smithsonian and the Academy contain, but could find no notice of it. 

 Holboll, Temminck and other authors, who admit the A. canescens, have gone 

 considerably into detail with regard to its variations and changes of plumage, 

 which, as well as those of A. linarius, are now well known, and a pretty defi- 

 nite " theory of variation " of the genus established. But seasonal or sexual 

 changes of plumage, even the most abnormal, could never produce the marked 

 difference in the size and shape of the bill, and the proportions of the feet and 

 toes. Having therefore been unable to find any description which ap- 

 plies even approximately, we have ventured to impose a name, feeling quite 

 assured, that if we are in error in so doing, some one will before long correct 

 the mistake. 



The specimens upon which the species is founded were, with one exception, 

 received from the Copenhagen Museum, to which we are indebted for a fine 

 series of several species, kindly transmitted for examination. They are label- 

 led as having been obtained in Greenland. 



jEgiothus fuscescens Coues. 



Aegiothus fuscescens Coues, Notes Ornith. Labrador, in Proc. Acad. Nat. Sci. 

 Phil., Aug. 1860, p. 222. 

 Diag. A. JEgiotho linario paululum minor, rostro fusco magno robusto, 

 jtlumulis brevibus sparsisque, superioribus partibus fuscis vix luteo striatis, 

 alis caudaque vix albido marginatis, lateribus distincte nee conflueute fusco- 

 striatis. 



[Nov. 



