OF GENERA. XXIX 



121. PoDiCEPS (Grehe). Bill forming a pointed cylindrical cone ; 

 front toes surrounded by a membranous border, but united at the 

 base only ; tail wanting. Page 529. 



122. CoLYMBUS (Diver). Bill forming a pointed cylindrical cone ; 

 front toes entirely palmated ; tail very short. Page 535. 



Family III. Alcid^. 



(auks.) 



Bill much flattened vertically (compressed) ; wings short ; legs 

 placed at the extremity of the body ; feet three-toed, palmated ; 

 tail short. Food, mostly fish, and captured by diving. 



123. Uria (Guillemot). Bill strong, nearly straight, sharp- 

 pointed, of moderate length ; nostrils basal, partly covered by a 

 feathered membrane ; first primary longest. Page 541. 



124. Mergijlus (Rotche). Bill strong, conical, slightly curved, 

 shorter than the head ; nostrils basal, partly covered by a feathered 

 membrane ; first and second primaries equal. Page 545. 



125. Fratercula (Pufiin). Bill shorter than the head, higher 

 than long, the ridge of the upper mandible higher than the crown ; 

 both mandibles much curved throughout, transversely furrowed, 

 notched at the tip ; nostrils basal, almost closed by a naked mem- 

 brane. Page 547. 



126. Alca (Auk). Bill large, sharp-edged, the basal half 

 feathered, the terminal part grooved laterally ; upper mandible 

 much curved towards the point ; nostrils nearly concealed by a 

 feathered membrane ; tail pointed. Page 550. 



Family I V". Peleoanid^. 



(pelicans.) 



Bill strong, edges of the mandibles minutely toothed ; wings long ; 

 legs short ; toes four, all connected by a membrane. 



127. Phalacrocorax (Cormorant). Bill straight, longer than 

 the head, compressed ; upper mandible much hooked at the point ; 

 face and throat naked ; inner edge of the middle claw serrated ; 

 tail rounded, rigid. Page 553. 



128. SuLA (Gannet). Bill straight, longer than the head, com- 

 pressed, taj^ering to a point, which is but slightly curved ; face and 

 throat naked ; inner edge of the middle claw serrated ; tail gradu- 

 ated. Page 558. 



Family V. Larid^. 



(gulls and PETRELS.) 



Edges of the mandibles smooth ; wings very long ; legs not 

 placed far behind ; three front toes united by a membrane, the 

 fourth free, sometimes very weak, or altogether wanting. Mostly 



