562 ALC^. 



B. Tail composed of 16 (rarely 18) feathers ; 



bill rather hmg:, the length from gape 



to tip about equal to that of the middle 



toe and claw ; sides of the head and 



neck with ornamental plumes ; 



during the breeding-season an ele- 

 vated horn at the base of the 



culmen H- CEEORBTi'NCHA, p. 609. 



II. Inner claw much more strongly curved 

 than the rest ; bill very deep and much 

 compressed ; the breadth of the upper 

 mandible at base much less than the 

 depth ; terminal portion transversely 

 grooved, the ridge of the culmen forming 

 a blunt razor-edge. Tail composed of 

 16 feathers. 



C. Basal outline of the terminal portion of 



the upper mandible convex ; lower 

 mandible without grooves. In the 

 breeding-sea!-on a deciduous saddle- 

 shaped shield covers the base of the 

 bill, and on each side of the crown 

 there is a lengthened crest of silky 

 golden feathers 12. Lunda, p. 61 1. 



D. Basal outline of the terminal portion 



of the upper mandible concave or 

 nearly straight and very oblique ; 

 terminal portion of lower mandible 

 grooved. In the breeding-season a 

 deciduous nasal shield, widest towards 

 the cutting-edge of the mandible ; 

 eyelids with deciduous homy append- 

 ages ; no oruamental nuptial crests . . 13. Fe.\tercula, p. 615. 



Subfamily I. ALCIN^. 



1. PLAUTUS. 



Type. _ 



Plautus, Brunnich, Zool. Fundamenfa, p. 78 (1 772) . . P. impennis. 



Pinguinus, Bonnat. Tahl. Encycl. Meth. i. p. 28 (1790) P. impennis. 



Torda, Bumeril, Zool. Analyt. p. 72 (1806) P. impennis. 



Chenalopex, Tieill. \_ex Moehring, Av. Gen. p. 65 



(1752)], N. Diet. d'Hist. Nat. xxiv. p. 132 (1818) . P. impennis. 



Mataeoptera, Gloger, Hand- ti. Hilfsb. p. 475 (1842) . P. impennis. 

 Gyralca, Steenstrup, Natiirh. Foren. Vidensk. Meddel. 



1855, p. 114 P. impennis. 



Mandibles greatly compressed and transversely grooved, the 

 outline of the culmen strongly curved downward. Inter-ramal 

 feathering extending far beyond a vertical line drawn from the 

 anterior border of the nasal opening, which is linear, and almost 

 entirely concealed by dense feathering extending to the anterior 

 border. Tail composed of 14 feathers. Metatarsus shorter than 

 the middle toe and claw. Size large. 



Range. Now extinct. Formerly inhabiting the coasts and islands 

 of the North Atlantic south of the Arctic circle. 



