I 



19. RissA. 313 



the primaries, the outer webs being darker, as are the margins of the 

 iiiiior webs up to the 4th ; the black spot is usually present on the 

 outer web of the 6th quill, but absent in one example ; under wing 

 grey, but paler than tlie mantle : bill short, culmen sharply 

 decurved, lemon-yellow with a greenish tinge ; tarsi and toes 

 vermilion, fading to yellow in preserved s])ecimens. Total length 

 15 inches, culmen 1-4, wing 11"75, tail 5'5, tarsus 1'2, middle toe 

 with claw I'S ; hind-toe sometimes with and sometimes without 

 a nail, presenting precisely the same amount of variation in develoj)- 

 ment as there is in li. trldactijla*. 



Adult in autumn. Similar, with dark hair-streaks before and 

 below the eye, dark auricular patches, and a slight greyish half- 

 collar below the nape. 



Immature. Like the above, but with more dark colour along the 

 outer webs of the second and third primaries. 



Young. Collar deeper and blacker ; feathers of the mantle tipped 

 with greyish white, the three outer primaries black on both sides 

 of their shafts : bill and tarsi brown ; otherwise similar. 



It will be observed that the young of this species differs from 

 that of a. tridacti/Ia in having no black band on the wing nor on 

 the tail. 



Hab. Lower part of Bering Sea, from the Kamschatkan side 

 (Commander Islands) to the Prybiloff and Aleutian Islands. 



a. Ad. St. Aleutian Islands. Purchased. 



/;. Juv. sk. Walrus I., Prybiloff group, II. Saunders CoU. 



Aleutians {G. li. Adams). 

 c-e. Ad. sk. St. George I., Prybiloff group, II. Saunders CoU. 



Aleutians {H. 'W. Elliott). 

 f-k. S ? ad. sk. St. George I., Prvbiloff group, Salvin-Godman Coll. 



Aleutians (H. 'W. Elliott). 

 I. Ad. sk. " North-west coast of America" J. Gould, Esq. [P.]. 



(? type of i. hrachyrhynchus). 

 m. d ad. sk. Bering Sea {S7iow). Seebohm CoU. 



* It is rciiKirkable tliat tliis form of 7?. hrcvirodris, with a tliorovghhj 

 devcliipid, tlumgh minute nail, slioiild not liave been considered as worthy 

 of sj)ecific distiuclion as li. kotsvhui or pollicaris I 



