l.VMILY rOlHCII'IDE. Gl.'KHKS. 



25 



WATER BIRDS. 



KEY TO THE SPECIES. 



FAMILY PODICIPID^E. 



Grebes. 



Toes, four ; three in front, one behind, with lobate webs. 



* Group 1. Wing, less than 6.50 inches long. 



Depth of bill at base of culmen, over .40. In summer: Bill, with black baud; throat, 

 black. 



In winter: Bill, without black band; throat, white. 



Fodilymhns podiceps. Picd'billed Grebe. Hell Diver. 



See No. 4. 



Depth of bill at base of culmen, less than .40. In stcmmer : Two small tufts of 

 brownish gray or buft-coloied feathers behind the eye; crown, nape, and throat, black. 



In vnnter : Plain colored, without black or buff on head; upper pluiriao;e, ffi-ayish black; 

 uuderparts, silvery white, often tinged with ash gray on throat and sides. 



Cohjmhits nxritus Horned Grebe. 

 See No. 2. 



* Group 2. Wing, over 6.50 inches long. 



In siamner : Crown, black; upper throat, gray^ lower throat and breast, chestnut rufous; 

 rest of uuderparts, silvery grayish white. 



In winter: No rufous brown on throat or breast. Colymhus hnlhwUi. HolboelPs Grebe. 



SeeXo. 1. 



* For directions for measurement, see pajje 9. 



