462 THE DIVING BIRDS — PYGOPODES. 



5. Cepphus. Size medium (wing about 6.50 to 7.50). 



c^. l>ill exceedingly variable in form, but never curved abruptly at the tip, always (except 



in Cerorhyncha) much shorter than the head, tlie gonydeal angle nmch nearer the base 



than the tip of the maTulible (except in Stjnthliboramphus). 



rfi. Distance from anterior border of nasal fosste to nearest feathering one fourth, or 



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



(Brd'-hj/mmplwrr.) 



6. Brachyramphus. Tar-si reticulate in front, not longer than the maxillary toraium (meas- 



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

 decidedly less than one half the culmen. Size small (wing less than 6.00 inches). 



7. Synthliboramphus. Tarsi scutellate in fiont, much longer than the maxillary tomium ; 



bill much couijin;ssed, the depth through the base much more than half the culmen. Size 

 of Brachyramphns. 



d^. Distance from anterior border of nasal fossce to nearest feathering one half, or more, 

 the distance frcjm the same point to the tip of the maxilla. (Phalerece.) 



8. Ciceronia. Bill small, witliout accessory pieces, except a small compressed knob at the 



base of the culmen 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 Akidrc (wing less than 4.00 inclies) 



9. Phaleris. Similar to Ciceronia, 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 filaments springing 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. Simorhyuchus. 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 upward to the rictus ; base of maxillary 

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

 in Phaleris, 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. Cyclorhynchus. Bill without accessory pieces ; mucb compressed, very deep, with 

 rounded outlines, the de])th through the base ec^ual to the chord of the culmen ; the 

 latter decidedly convex ; mandible falcate, or strongly recurved, and sharp-pointed. A 

 single line of pointed white feathers behind the eye. Size of Simorhyuchus. 



12. Ptychoramphiis. Bill without supernumerary pieces, and head without ornamental 

 fcatlu-rs. Bill elongate-conical, the maxilla much broader than deep at the base ; culmen 

 nearly straight, and gonys likewise little curved, but decidedly ascending from the men- 

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

 Size small (wing about 5.00 inches). 



1.3. Cerorhyncha. Bill large and much compressed, nearly as long as the head, height 

 neaily half tiie 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). 

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

 the angle of the mouth. 

 Sub-family Fraterculin^. 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. Fratercula. Deciduous nasal 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 sulcate ; 

 eyelids furnished with deciduous horny plates ; head not tufted. 



