BIRDS OF THE HAWAIIAN GROUP. 



Genus I/A'RTJS Linn^us. 



a. Head entirely white in the summer adults. 



b. Primaries uniform pale grey, with no black, and fading gradually 

 into white at the tips (larger, wing more than 16.00). Head, neck, tail and under 

 parts white ; mantle grey ; the scapulars and secondaries white at their tips. Female 

 smaller, often considerably so. . Adult in winter: Mottled and streaked with pale 

 brown on the head and neck; back and under parts also mottled. Immature: The 

 mottling on the upper surface gradually disappears and for a short time the bird ap- 

 pears to be a creamy white. Young: Both the upper and under surface streaked and 

 mottled with ash-brown on a paler ground color ; the feathers of the mantle margined 

 with huffish white which produces a creamy appearance; upper, and under coverts 

 rather boldly marked with brown (Saunders). Length about 25.00-28.00, wing 16.25- 

 18.00 (17.12), tail 7.00-7.50, culmen 2.30-2.70, tarsus 2.40-2.78 (2.57), middle toe 

 with claw 2.35-2.75 (2.55). Hab. Bering Sea and adjacent waters northward to Point 

 Barrow ; southward in winter to Japan (Ridgway ) . Kauai,' Maui. 



I. I/, barrovianus^ Ridgw. Point Barrow Gull. 



bb. Primaries marked with distinct white tips and dark (black) subtermi- 



nal spaces ; the two outer primaries with a distinct grey wedge on the inner web in 



the summer adults; depth of bill through the angle .50 or more; mantle blue-grey 



or dark pearl-grey in adults. 



C. Larger, length 20.00-23.00, culmen 1.65-2. 15, -mantle-darker grey 

 than in the following species; scapulars and secondaries broadly tipped 'with white; 

 the outer primary with a large portion of black ; the first, chiefly black with about 

 2.00 of the terminal portion white; the second, with a small grey j^edge basally; 

 the third, fourth and fifth, black with white tips and increasing grey wedges ; bill, 

 bright yellow with an irregularly shaped spot of intense carmine near the' tip of the 

 lower mandible, and a dark spot or bar usually anterior to this on one or both mandi- 

 bles. Female smaller and duller in color. Adult in winter: Like the above but head 

 and neck streaked with greyish brown. Immature: Autumn birds of the second year 

 show grey on the mantle ; upper tail coverts begin to show grey at their bases ; tail 

 feathers more uniform umber brown than before, though the coverts are whiter ; under 

 parts whitish brown without distinct spots ; bill yellower at the base. Young: Much 

 darker brown throughout ; no signs of grey on the secondaries nor the basal portion 

 of the inner primaries, the paler inner webs being nearly dull brown; tail coverts 



2 The single specimen in the Museum coUetflion is one of two taken on the island of Kauai by Mr. Francis Gay. Both specimens were 

 taken late in the autumn months. While neither specimen agrees as closely with the descriptions at hand as would be desirable, I have 

 seen fit to refer them to barrovianus, believing them to be immature birds of that form. This is probably the undetermined species mentioned 

 by Kittlltz. The following measurements are taken from the Museum specimen No. 9305 ; I,ength 25.50, culmen 2.00, tail 6.50, tarsus 2.85, 

 toe 2.75; locality, Kauai, H. I.; date, 1899, autumn. There is also a specimen in the cabinet of St, I^ouis College, Honolulu, taken on Maui 

 by Brother Matthias. 



iLarusglaucus, Briinn, froml^aysan (Z>)-. Schauiniland); Hawaii (Henshaw, in Auk, Vol, XVII., p. 201). 



[262] 



