SABINE S GULL. 



311 



genus more in the form of the bill, and in the dimensions of the 

 tarsus and tibia. 



" In this specimen of the L. Sahini, in the autumnal phimage of the first year, the 

 forehead^ space immediately above the eye, and between it and the bill (with the 

 exception of the narrow line of greyish-black closely encircling the front and lower 

 part of the eye), upper part of the throat, and sides of the neck, are white ; crown, 

 nape, and back of the neck, blacldsh-grey ; back, scapulars, gi'eater and lesser wing- 

 coverts, blackish-grey, tinged with yellowish-brown, the extremity of every feather 

 varying from greyish-white to white, as it approaches the tail ; under part of the 

 throat and upper part of the breast, pale ash-colour ; lower breast and all the under 

 plumage, white ; shafts of the fu-st six primaries brownish-black at base, becoming 

 gradually darker towards the extremity, where they are black in the first three, but 

 in the fourth, fifth, and sixth, they assimilate in colour to the feather at that part, 

 which is white ; the entire of the outer webs of the first five, black ; the inner webs, 

 with a broad edging of white to within from one to two inches of the end, which part 

 is black in the first three, but tipped with white in the fourth and fifth ; in the sixth 

 the inner web is white, the outer black, excepting for three or four lines from the tip, 

 where it is white, and again, at about an iuch from the end, where a white spot of 

 an oval shape appears.* Feathers of the tail twelve in number, white, with black 

 tips ; in the two shortest the latter colour extends upwards of an inch from the end, 

 in the outer web especially ; of the other feathers, the black prevails in a less degree 

 as they increase in length ; upper and under tail-covei'ts white. 



'Length (total) 

 of tail 



„ of mng from carpus to end of first quill . 



„ of bill fr-om forehead to point 



,, of bill from rictus to point .... 



,, of tibia bare of feathers from the tarsal joint for 



„ of tarsus ....... 



„ of midcUe toe and nail ..... 



„ of outer toe and nail ..... 



„ of inner toe and nail ..... 



„ of hinder toef and nail .... 



Depth of fork of tail 



\_March 1838. — Having just seen the notes of 'the late Mr. Montgomery on this 



in. 



lin. 



12 







4 



9 



10 











10 



1 



5 







9 



1 



4 



1 



H 



1 



1 





 



9i 



2" 



1 



0" 



* This marldng of the sixth primary is just the opposite of that observed by 

 Mr. Sabine in some mature specimens, in which its prevailing colour was white, 

 " with sometimes a l)lack spot near the cud." Dr. Richardson has rcuiiu-ked, in the 

 ' Fauna Bor.-Aracr.,' that this primary is subject to variation. 



t This is placed so liigh that the point of the nail does not reach witliiu l^ line 

 of the ground. 



