BIEI>S OF NORTH AND MIDDLE AMERICA. 713 



Alia impennis Boddaert, Tabl. PL Enl., 1783, 22 (PI. Enl., pi. 367). 



Plautus impennis Steenstrup, Vid. Med. Nat. Forh. Kjobenhavn, 1855, 14; 

 Nat. For. Vid. Med., 1855, 33-116.— Preyer, Journ. fiir Orn., 1862, 110, 337. 

 — Baird, Brewer, and Ridgway, Water Birds N. Am., ii, 1884, 467. — 

 American Ornithologists' Union, Check List, 1886, and 2d ed., 1895, 

 no. 33; 3d ed., 1910, p. 32.— Sharpe, Handb. Birds Great Brit., iv, 1897, 

 111, pL 105. —Grant, Cat. Birds Brit. Mus., xxvi, 1898, 563.— Thayer, 

 Auk, xxii, 1905, 300, pis. 13, 14 (as to recent purchase of mounted specimen 

 and 3 eggs); xxix, 1912, 208, pi. 12 (account of eggs in Thayer Museum). 



P[lautus] impennis Ridgway, Man. N. Am. Birds, 1887, 19. 



[Plautus] impennis Sharpe, Hand-list, i, 1899, 130. — Forbes and Robinson, 

 Bull. Liverp. Mus., ii, no. 2, 1899, 51. 



P[inguinus] impennis Bonnaterre, Tabl. Enc. Meth., i, 1790, 29, pi. 10, fig. 2. 



Pingouin impennis Lacepede and Daudin, in Didot ed. Buffon Hist. Nat. 

 Quadr., xiv, 1799 (1802), 313. 



[Chenalopex] impennis Gray, Hand-list, iii, 1871, 95, no. 10773. 



Alca borealis Forster, Synopt. Cat. Brit. Birds, 1817, 29. 



[^^ca] mdior Merrem, in Ersch u. Gruber, EncycL, sect, i, ii, 1819, 407. 



Genus ALCA Linnaeus. 



Alca Linn^us, Syst. Nat., ed. 10, i, 1758, 130; ed. 12, i, 1766, 210. (Type, by 



tautonymy, Alca torda Linnaeus.) 

 Pingouin Lacepede, in Buffon Hist. Nat., Quadr., Didot ed., xiv, 1799 (1802), 



313. (Type, Alca torda Linnaeus.) 

 Utamania Leach, Syst. Cat. Birds and Mam. Brit. Mus., 1816, 42. 



Large Alcidse (wing 188-201 mm.) with the deep and compressed and 

 transversely-grooved bill much shorter than head; tail graduated, of 

 12 reotrices, and wings well-developed (adapted for flight). 



Bill much shorter than head, the distance from anterior end of 

 nostril to tip of maxilla much less than from same point to rictus 

 much compressed, its width at anterior end of nostril equal to only 

 about half the depth of maxilla at same point; culmen strongly 

 arched, the tip of maxiUa strongly uncinate; tomia nearly straight 

 to near tip where strongly decurved; gonydeal angle prominent;, 

 the gonys ascending and faintly concave distally; mandibular rami 

 densely covered with soft, velvety feathering except along upper 

 edge, the anterior outline of the feathering forming a gently curved 

 (convex) line to the base of gonys; whole loral region and nasal 

 fossae densely covered with short, soft velvety feathering, which 

 overhangs the upper edge of the longitudinal, sht-like nostril, the 

 anterior edge of this feathering forming a slightly curved (convex) 

 strongly oblique line from anterior end of nostril to base of culmen; 

 a narrow prominent lamina saddled over base of maxilla, against 

 frontal and loral feathering, at the lower end continued backward as a 

 prominent longitudinal ridge, between nostril and tomium, to the 

 rictus, the mandible also with a similar ridge along upper and anterior 

 portions of the ramus ; sides of maxilla with two or three rather broad 



