1082 



SYSTEMA TIC SYNOPSIS. — PYGOPODES — ALCjE. 



Analysis of Species and Subspecies. 



Depth of bill opposite nostrils not one-third the lengtli of culmen. 



Bill comparatively slender, not dilated along edge of upper mandible at base ; culmen, commissure, and gonys: 



curved. Atlantic troile 



Bill stouter, somewhat dilated along edges of upper mandible at base ; culmen, rictus, and gonys nearly straight. 



Pacific troile californica 



Depth of bill opposite nostrils more than one-third the length of culmen. 



Bill very stout, thick, deep, much dilated along edges of upper mandible at base ; culmen, commissure, and gonys 



curved. Atlantic lomvia 



Bill less stout. Pacific ... lomvia arra 



U. troi'le. (Nom. propr. of uHcertain reference. "Possibly a compliment to Troil, the Ice- 

 lander." Newton. Figs. 742, 743, 746.) Common or Foolish Guillemot, Guillem or 

 GwiLYM. Common Murre. Tinker or Tinkershire. Kiddaw or Skiddaw. Mar- 

 rock. WiLLOCK. ScuTTOCK. ScouT. Strany. Lavy, Frowl. (Several of these 



Fig. 742. — Common Guillemot, or Murre, nearly 

 nat. size. (From Elliott.) 



local British names shared with other Murres, 

 and with the Razor-billed Auk.) Adult $ 9 > 

 in summer : Head and neck all around rich dark 

 maroon brown, changing on upper parts into 

 dark slaty -brown, nearly uniform, but most 

 feathers of back and rump with slightly lighter, 

 more grayish -brown, edges. Secondaries nar- 

 rowly but distinctly tipped with white. Under parts from throat pure white ; sides and flanks 

 marked with dusky or slaty ; lining of wings varied with white and dusky. Bill black ; mouth 

 yellow ; eyes brown ; feet blackish. In some cases, not in most, a white " eye-glass," consist- 

 ing of a rim around eye and handle back of eye 

 in the furrow of the plumage (such birds, which 

 are of either sex, being the so-called Ringed 

 or Bridled Guillemot, U. ringvia). In winter: 

 White of under parts reaching bill, on sides of 

 head to level of commissure, farther around on 

 sides of neck, leaving only a narrow isthmus 

 of dark color ; the two colors shading without 

 distinct line of demarcation ; usually a spur of 

 dark color in the furrow behind eye. Young, first winter : Similar to adults at that season 

 but with less white on sides of head and slight dusky mottling on jugulum; bill shorter and 

 weaker, and, like the feet, in part light-colored. Fledglings dusky brownish, with white 

 breast and belly, and whitish about head and neck. Length 17.00; extent 80.00; wing 

 8.00; tail 2.25; tarsusl.40; middle toe and claw 2. 10; outer 2.00; inner 1.70; culmen 1.75; 

 gape 2.50; gonys 1.15; depth of bill at base 0.55; width 0.30. (The figures are aver- 

 ages of adults; total range of variation 15.00-18.00 in length, and other measurements to 



Fia. 743. — Common Guillemot, nat. size. 



