462 



THE DIVING BIRDS — PYGOP JDES. 



5. CepphuB. Size inediuni (wing about 6.50 to 7.50). 



c *. ]?ill exceedingly variable in form, but never curved abruptly at the tip, always (except 



in Ccrorhijncha) nuicli shorter than the head, the gonydeal angle much nearer the base 



than the tip of the mandible (except in Sijnthlibommj)hus), 



d^. Distance from anterior border of na.sal fossoo to nearest feathering one fourth, or 



less than one fourth, of the distance fron\ the same point to the tip of the maxilla. 



{Bnichyramj^Iiec-) 



6. Brachyramphus. Tarsi reticulate in front, not longer than the maxillary tomium (meas- 



ured to base of horny portion) ; bill moderately compressed, the depth through the base 

 decidedly less than one half the culnien. Size small (wing less than COO inches). 



7. SyntbliboramphuB. Tarsi scutelLite in front, much longer • nan the maxillary tomium ; 



bill much conii>ressed, the depth through the base much more than half the culmen. Size 

 of Bmchymmphiin. 



d\ Distance from anterior border of nasal fossis to nearest feathering one half, or more, 

 the distiince from the same point to the tip of the maxilla. (Plmlcrece.) 



8. Ciceronia. Bill small, without accessory pieces, except a small compressed knob at the 



base of the culmun in the breeding-season. Head without crests, but ornamented (in 

 the adult) with white acicular feathers over frontal and loral regions. Size smallest 

 of the Alcidiv (wing less than 4.00 inclu's) 



9. PhaleriB. Similar to Ckernnia, but culmen destitute of knob, even in breeding-season, the 



head ornamented with a long, slender, recurved crest on the fore part of the crown, sev- 

 eral long, slender, whitish iilaments -ipringing from above the eye, a postocular series of 

 long, slender, pointed, white feathers, and a similar series crossing the cheeks. Size a 

 little larger than Ciceronia (wing about 4.50 inches). 



10. Simorhynchus. In the breeding-season : Covering of the bill complicated by the fol- 

 lowing accessory pieces, all of which are shed before winter : base of mandibular rami 

 developed into a prominent broad plate, curving upwanl to the rictus ; base of maxillary 

 tomia developed into a large semicircular concave plate. A frontal recurved crest, as 

 in Pluderis, but no other ornaments except a postocular line of narrow, pointed, white 

 feathers. In winter: Bill simple, as in Phaleris. Size larger (wing 5.00 inches or 

 more). 



11. Cyclorbynchus. Bill without accessory pieces ; much compressed, very deep, with 

 rounded outlines, the dejjth through the base e(iual to the chord of the culmen ; the 

 latter decidedly convex ; mandi))le falcate, or strongly recurved, and .sharp-pointed. A 

 single line of jjointed white feathers behind the eye. Size of Simorhynchus. 



12. PtychoramphuB. Bill without supernumerary pieced, and head without ornamental 

 feathers. Bill elongitte-conical, the maxilla much Ijroader than deep at the base ; culmen 

 nearly straight, and gonys likewise little curved, l)ut decidedly ascending from the men- 

 tal angle. Nasal fossre very large (occupying nearly the basal half of the mandible). 

 Size small (wing about 5,00 inches). 



13. Cerorbyncha. Bill large and much compressed, nearly as Ion ,• as the head, height 

 nearly half the length, the culmen strongly curved, the gonys slightly concave, the men- 

 tal angle being very prominent. Cere surmounted in the breeding-season by a prominent 

 vertical compressed knob or horn. Adult with a postocular and mystacial series of 

 narrow, pointed white feathers. Size large (wing about 7.00 inches). 



U Inner claw much larger and more strongly curved than the others. A tumid " rosette " at 



the angle of the mouth. 

 Sub-family FuATERcuiiiNiE. Bill excessively compressed, its depth at the base nearly or quite 

 equal to the chord of the culmen, the terminal half transversely grooved, the basal 

 portion ornamented in the breeding-season by a greater or less number of supernumerary 

 deciduous pieces. 



14. Frateroula. Deciduous na.sal shield, rapidly diminishing in width toward the top ; 

 basal outline of the mandible concave ; maxillary sulci and anterior outline of the nasal 

 shield with the concave sides posterior ; terminal half of mandible obliquely sulcata ; 

 eyelids furnished with deciduous horny plates ; head not tufted. 



