SyXTIILIBOR.UII'UCS. 13 



b\ 'Wing 5.00 or more; adult in breeding season with several conspicuous de- 

 ciduous plates on basal portion of bill, including a roundish or semicir- 

 cular piece at corner of mouth ; no white feathers between bill and eye ; 

 belly never whitish. (Subgenus Simm-hynchus.) Breeding plumage: 

 Bill bright orange-red, the tip horn-colored. Winter plumage : Bill horn- 

 colored, much smaller, through loss of the deciduous pieces. Young : 

 Frontal crest and white feathers beneath eye wanting, or but slight!}' 

 developed; bill much smaller, duskj' brownish. Length 8. 50-10. SO; 

 wing about 5.25. Egg 2.14-1.49. JIab. Coasts of the North Pacific 

 from Kadiak, Unalashka, and the Prybilof Islands through the Aleutian 

 chain to Kamtschatka and northern Japan. 



18. S. cristatellus (Pall.). Crested Auklet. 

 fc'. ATing less than 4.50 ; adult in breeding season without conspicuous deciduous 

 plates on basal portion; belly whitish; a more or less distinct patch of 

 narrow, pointed, white feathers between bill and cj-e (indistinct or ob- 

 solete in young). (.Subgenus Fhalcris Temminck.) Breeding plumage : 

 Bill tlidl purplish red, the tip whitish. Winter pAumage not materially 

 different. Young: Frontal crest and white feathers on sides of head 

 wanting or barely indicated ; bill dusky. Downy young : Uniform sooty 

 slate, lighter beneatli. Length 7.10-8.30, wing 4.10-4.25, culmen .35-.40. 

 Hab. Coasts of the North Pacific, from L^nalashka through the Aleutian 

 chain to Kamtschatka... 10. S. pygmseus (Gmel.). Whiskered Auklet. 

 fl'. Wing not more than 4.00 ; adult without frontal crest; lower parts white, some- 

 times blotched with dusky; scapulars with more or less white; base of bill 

 ■with a small compressed knob on top. (Subgenus Ciceronia Reich.) Breed- 

 ing phimage : Lower parts white, moi'c or less spotted or blotched with 

 dusky, this often forming a distinct band across the chest. Winter plumage : 

 Lower parts, including sides of neck, entirely white ; white ornamental 

 fcathei's of forehead, etc., usually less developed. Young : Similar to winter 

 plumage, but bill smaller, scapulars more extensively white, and white orna- 

 mental feathers of forehead, etc., wanting. Downy young : Uniform sooty 

 slate, paler and grayer on lower parts. Length 5.50-7.20, wing 3.50-4.00, 

 culmen .35-40. Eggs 1.58 X 1-10. Hab. Coasts of the North Pacific, from 

 Japan and southern Alaska to the Aleutian and Prj'bilof Islands. 



20. S. pusillus (P.vll.). Least Aaklet. 



Genus SYNTHLIBORAMPHUS Brandt. (Page 9, pi. VI., fig. 1.) 



Species. 



Common Characters. — Above plumbeous, beneath white. Breeding plumage : 

 Chin and part, or whole, of throat dusky ; top of head with a broad white stripe 

 along each side ; sides, from neck to flanks, uniform sooty blackish. Tn;!^er plumage : 

 Whole throat white, the chin ]ilumbeou3; no white stripes on top of head; sides 

 and flanks white, striped with slaty. 



