NATURAL SCIENCES OP PHILADELPHIA. 229 



Family PODICIPID^. 



Char. Feathers of forehead not reaching to the nostrils. Nostrils linear, 

 oblong, sometimes quite broadly oval, without dependent lobe. Lores naked. 

 Tertials long, reaching to the tip of the primaries in the closed wings. Tail 

 rudimentary. Tarsus and toes covered with regular, long, narrow, transverse 

 scntellss. Toes lobed, connected at base by a membrane. Tibise feathered to 

 the joint. Claws weak, broad, short, flat. Posterior edge of tarsus serrated, 

 formed by a double row of small, pointed scales. Lobe of hind toe large. Size 

 moderate, or very small ; general form rather slender ; body depressed ; neck 

 long ; crests or ruffs usually present ; the back never spotted. 



The preceding diagnosis expresses very briefly the more prominent charac- 

 ters of a group of birds composing the subfamily Podicipina' of modern authors. 

 It corresponds with the Coli/mbi pedibiis pahnatis and pedibus lohatis of Gmelin, 

 nearly with the Cepphi and Cohjmhi of Pallas, and with the genera Colymhus 

 and Podiceps of Latham. Although related to the Colymbida in most points 

 of structure and habits, they nevertheless differ in so many and so essential 

 characters, that a single family cannot, without great latitude of definition, 

 contain the two groups. We have, therefore, restricted the ColymbidcB to the 

 ColymbincE of authors, and raised the PodicipincB to the rank of a distinct 

 family. 



Two subfamilies are represented in North America . 



Subfamily PODICIPINA. 

 Char. Bill moderately stoiit, or very slender. Commissure not abruptly 

 decurved at the end. Nostrils linear. Bare loral space narrow and linear. 

 Feathers of the head with their shafts normal. Tarsus at least three-fourths 

 the middle toe; generally but little, if any, shorter. Toes connected at base 

 for a moderate distance, the lobe of the hind toe broad. Usually (always ?) 

 with more or less conspicuous crests and ruffs. 



Genus I. JEchmophorus Coues. N. G-. 



Gen. Char. Bill very long, exceeding the head, straight or very slightly 

 recurved, slender, attenuated towards the tip, which is very acute. Culmen 

 straight or slightly concave. Commissure about straight. Gonys convex 

 throughout its whole length, the angle scarcely appreciable. Nasal groove 

 long, shallow, and narrow. Bare loral space very narrow. Wings rather 

 long, pointed, the outer primaries much attenuated. Legs very long. Tarsus 

 as long as the middle toe and claw, exceeding the bill, excessively com- 

 pressed. Outer lateral toe much longer than the middle. Lobes united at 

 base for a very short distance. Size large ; body slender ; neck very long. 

 Head with moderate crests, but without decided ruffs ? 



Type. Podiceps occidentalism Lawr. 



1. ^CHMOPHORUS OCCIDENTALIS (Lawr.) 



Podiceps occidentalis, Lawr. 1858. 



Char. Length about 29 inches ; wing 8*25 ; bill or tarsus 3*00. Bill equal 

 to tarsus, straight, dark colored, except terminally and along the cutting 

 edges. Gonys straight from base to angle, and nearly so from angle to tip. 

 Feathers between eye and nostril grayish ash. 



Eabitat. Pacific coast of North America. 



2. AcHMOPHORus Claekii (Lawr). 



Podiceps Clarkii, Lawr. 1858. 



Char. Much smaller than A. occidentalis. Length 22 inches ; wing 7 ; 

 bill 2-25 ; tarsus 2-75 ; bill rather shorter than tarsus, exceedingly acute, 

 slightly recurved ; the gonys regularly much curved from base to tip, the 

 angle scarcely apparent. Feathers between eye and nostril white. 



Eabitat. Pacific coast of North America. 



1862.] 



