230 PROCEEDINGS OP THE ACADEMY OF 



Genus II. Podiceps Latham. 



Colymbus, Briss. 1760, nee. Linn, et auct. IlL 1811 ; Pall. 1811. 



Podiceps, Lath. 1790 ; (typus Col. cristatus, Linn.) nee Kaup. 1829. 



Pedetaithya, Kaup. 1829 ; typus Col. griseigena, Eudd. 1783.) 



Lopharthyia, Kaup. 1829; (typus Col. cristatus, Linn. Podiceps, Lath. 1790.) 



Dytes, Kaup. 1829; (typus Col. cornutus, Gmel.) 



Proctopus, Kaup. 1829; (typus Col. auritus.) 



Otodytes, Reichenbach, 1853 ; (typus idem.) 

 Gen. Char. Bill moderately stout ; usually more or less compressed ; as 

 long as, or rather shorter than, the head ; not equalling the tarsus. Culmen 

 convex, occasionally nearly or quite straight. Commissure about straight. 

 Tarsus shorter than the middle toe and claw. Outer lateral but little, if any, 

 longer than the middle toe. Body depressed, moderately full ; head always 

 with more or less conspicuous crests and ruffs. 



Although the characters of the genus are drawn so as to exclude both the 

 foregoing and succeeding genus, the North American species comprised in it, 

 are sufficiently dissimilar in form to have caused the instituting of several 

 subgenera. These may be characterized and arranged as follows : — 



A. Tarsus'equal to the middle toe without the claw. 



I. Bill equal to the head, four-fifths the tarsus. Bill 



much compressed, lateral outlines a little con- 

 cave. Crests and ruffs very long and conspicu- 

 ous Podiceps, Lath. 



II. Bill much shorter than the head, but little more 



than half the tarsus. 



1. Bill compressed, higher than broad at the nos- 

 trils ; crests and ruffs, especially the latter, very 



long and full Dytes, Kaup. 



2. Bill depressed, broader than high at the nostrils ; 



crests and ruffs more moderate Proctopus, Kaup. 



B. Tarsus about four-fifths the middle toe and claw. 



III. Bill variable in length, always qiiite stout ; outer 

 lateral but little longer than the middle toe ; 



crests and ruffs rather short Pedetaithya, Kaup. 



1. Podiceps ceistatus Latham. 



Colymbus C7-istatus, Linn. 1766 ; Pall. 1811 ; 111. 1811. C. urinator, Linn. 

 1766, juv. Podiceps crist. Lath. 1790, et auct. 

 Habitat. Europa ; Amer. Sept. 



2. Podiceps Cooperi Lawrence. 



Sp. Char. Bill large and strong, as long as the head, very stout at the 

 base, the tip very acute and considerably decurved. Upper mandible with 

 the culmen very slightly concave on the basal half, the terminal portion re- 

 gularly convex. Commissure irregularly sinuate to the nostrils, then regu- 

 larly decurved, the radius of curvature decreasing towards the tip. Lower 

 mandible without a groove along the symphysis of the rami beyond the 

 angle, the tip decurved and very acute. Lower outline concave, both ante- 

 rior and posterior to the angle, which is prominent and marked ; the con- 

 cavity is very decided in the former. First and second primaries longest, 

 third but little shorter. Tarsi and toes as in P. cristatus. 



Young. Upper mandible dusky, except the tip and extreme base, which 

 are yellowish, as is also the lower mandible, except a central dusky greenish 

 space. No white space between eye and nostril. Slight indications of -a 

 crest, but none at all of a ruff. Crown, and median dorsal line of neck, deep 

 blackish brown, darkest on the former. Upper parts brownish black, darkest 

 on the scapulars and lower part of the back, all the feathers, especially an- 



[April, 



