Family COLYMBIDAE. 



Podiceps cristatus (L.) Great Crested Grebe. 



(Plate 190, fig. a-b). 

 (Snouckaert : Avifauna Neerlandica, p. 137, No. 328). 



Colour of surface of shell : 



Average dimensions: 

 Average weight of shell: 

 Texture of shell : 



Shape : 



Nest: 



Site of nest: 

 Number of eggs: 

 Breeding season: 

 Duration of incubation: 

 * Remarks : 



the shell proper is pale greenish blue, but 

 is covered with a chalky, white layer which 

 gradually assumes a colour ranging from 

 yellow to dark brown;* when light pene- 

 trates through it, it shows through deep 

 bluish green. 



The chalky layer adheres in the case of eggs 

 of the genus Podiceps iiuich more closely 

 to the shell proper than, e.g., in the case of 

 Phalacrocorax carbo. 



54 ^■'. 36 millimetres. 



about 4 grams. 



the shell proper is fine and smoothly granu- 

 lated. 



elongated, bi-conical, or rounded at both 

 ends, and more or less bellied. 



consists of vegetable materials. 



by the edge of lakes, reed-pools, etc. 



3—5, mostly 4. 



May— Juno. 



about 3 weeks. 



According to Baedeker '). the eggs assume 

 a yellow colour on soil containing iron- 

 ochre; a greyish brown or blackish colour 

 on peat soil. 



') Die Eier dcr europaischen Vogcl, I (text after Plate 10, I). 



