NATURAL SCIENCES OF PHILADELPHIA. 195 



the shaft. Upper tail coverts long, extending to within half an inch of the tips 

 of the central tail feathers, black, except the outer series, which are wliite with 

 dusky markings. Central tail feathers brownish black, the rest suecessively 

 lighter, and all with a narrow border of white. Jugulum with a very decided 

 light brownish sutFiision, (much as in A. maculata,) and, togetlier with the sides 

 under the wings to some distance, with rounded obsolete spots and streaks of 

 dusky. Throat and under parts generally white, immaculate. Bill, legs and 

 feet black. Young in August. Dimensions and proportioQS as in the adult. 

 Upper parts a nearly uniform liijlit ashy browa, deeper on the rump, each 

 feather with a central dark field and with a light edge. Traces of the brownish 

 black of the adult on the scapulars. Breast and jugulum with the suffusioa 

 very light reddish brown, the streaks sparse and very indistinct. 



Length 7-25, extent 15-25, wing 4-9. Bill above, tarsus and middle toe about 

 •85. 



Habitat. — North America, east of the Rocky Mountains. Not on the Atlantic 

 coast. (?) 



The preceding diagnosis expresses the most essential characters of a Sand- 

 piper, hitherto confounded with the A. Bonapartei, but nevertheless perfectly 

 distinct from that or any other species recognized as an inhabitant of North 

 America. Though a true Actodromas, and very closely related to the A. minu- 

 tilla and maculata, a similaritj' in size, in changes of plumage, and, to some 

 extent, in general appearance, has caused it to be referred to A. Bonapartei, 

 which, however, belongs to a group subgenerically distinct. But the two difler 

 very materially both in tints and in the pattern of coloration of the upper par's, 

 and in the character of the upper tail coverts and the jugulum. The following 

 brief schedule will express tbe chief distinctive features of each, and render 

 further comparison unnecessary. 



A. Bairdii. — Length about 7-25 inches. Bill slender, entirely black. Feathers 

 extending on the lower mandible much beyond those on the upper. Edging of 

 scapulars light buff color, indented. Breast and jugulum with a decided 

 brownish suffusion, the markings rounded, sparse, rattier obsolete. Upper tail 

 coverts much lengthened, black; central tail featliers projictiug but litile, the 

 emargination of the tail slight. 



A. Bonapartei. — Length about 7'50 inches. Bill stout, flesh colored at base 

 below. Feathers extending on the lower mandible but little if any beyond 

 those on the upper. Edging of scapulars bright chestnut, scarcely indented. 

 Jugulum and breast with a scarcely appreciable ashy wash, the streaks narrow, 

 numerous, well defined. Upper tail coverts moderate, white ; the central tail 

 feathers considerably projecting, and tail quite deeply emarginate. 



The species is a true Actodromas, and belongs subgenerically to tlie same 

 group as A. minutilla and maculata, with both of which it is very closely related, 

 and requires comparison. In size it is exactly intermediate between the two, 

 exceeding the minutilla by about as much as it is itself surpassed by the macu- 

 lata. The slender black bill is very similar to that of mmutilla, and the general 

 pattern of coloration almost identical. The colors, however, are everywhere 

 much lighter; the edgings of the feathers of the upper parts being of a light 

 reddish yellow or buff, instead of the bright chestnut red of minutdla ; while 

 the streaks upon the breast are fewer, less distinct and more rounded. It is 

 considerably smaller than A. mac-idata: there is nothing of the abrupt transition 

 from the dark crown to the much lighter hind neck, so conspicuous in the 

 latter; the tertials want the bright reddish edgings, and the pattern of color- 

 ation of the upper parts are quite different. While the suffusion of the breast 

 and jugulum is much the same, the markings are more rounded, sparse and 

 indistinct. There is also a great difference in the bill, as regards size, shape 

 and color. The species differs from both minutilla and maculata in one important 

 respect, — the character of the changes of plumage it undergoes. The young 

 of both the former are usually quite as bright, if not brighter, than the adults ; 



1861.] 



