OOLOGY. 



11 



The young, a few days old, have the bill blact, with yellow tip, the 

 feet dull blackish, webs partly dull whitish. The general plumage is 

 black, mottled with yellowish-brown, much paler, inclining to white, 

 below, as usual in this family of gulls. 



In embryos about to be hatched, the bill and feet are nearly colorless; 

 the former somewhat mottled with black. The general plumage, so far 

 as it can be determined from wet preparations, is much as has been 

 already described. 



Sterna vittata, Gm. (p. 17.) 



The single eigg is laid on high and broken ground, usually under the 

 lee of a tuft of grass, and with little or no preparation. First found 

 iisrovember 7. The shell is thin, elastic, and iinely granular in texture, 

 of general olive-green color. The ground-color varies widely, as usual 

 in this family of birds, from rather clear green, with a suspicion of drab, 

 to a decided brownish drab. Superficial markings are chocolate-brown 

 of several shades, disposed in irregular spots and blotches, rather more 

 thickly crowded toward the larger end. Deep markings show various 

 shades of bluish slate-color, according to the thickness of the overlying 

 deposit. The shape of the Qgg is a regular ovoid, and the measurements 

 are as follows : — 



Smith son. No. 



Orig. No. 



Measurements. 



17188 



61 



1.78 X 1.22 



17187 



75 



1. 82 X 1. 29 



17184 



76 



1.82X 1.27 



17185 



77 



1. 83 X 1. 30 



17186 



78 



1. 75 X 1. 23 



17189 



96 



1. 85 X 1. 20 





97 



1. 80 X 1. 25 

 1. 70 X 1. 27 



The young, when first fledged, is yellowish-brown, spotted irregularly 

 with black ; its bill, toes, and tarsus dirty-orange, blackening toward 

 tips. Later, the colors grow darker, feet and tarsi becoming orange- 

 red. It is as large as a chick, and very unlike the old bird in marking 

 and general appearance. Specimens of the embryos have been sent to 

 Professor Morse for examination. 



DlOMEDBA EXULANS, Linn. (p. 19.) 



Nests are on tall mounds, built up of grass to the height of two or 

 more feet from the ground, and, being of different heights, seem to have 



