ANATIDAE. 



FULIGULA FULIQULA (L.). 



The chalk layer lying immediately under the glutinous layer is 

 coloured sea green; under it follows a ;'f//oim/; layer that is distinctly 

 tinged with soft pink ; the fundamental layer is coloured sea green. 



SOMATERIA MOLLISSIMA (L.). 



The chalk layer immediately underlying the more or less yellow- 

 ish tinted glutinous layer, is coloured sea green; the next layers 

 under it, down to the inner membrane, are greyish white with a 

 very faint greenish tinge. 



In all the eggshells of the above mentioned Anatidac that I exa- 

 mined, with the exception only of Somateria mollissima, which 

 thereby shows an oological relationship to Anseridae, I observed 

 that the chalk layer immediately underlying the glutinous layer is 

 much more strongly glossy than the glutinous layer itself; in other 

 words: it is more glossy than the exterior surface of the eggshell. 



The peculiar smooth, soapy as it were, character of the exterior 

 of the eggshells of all Anatidae is no doubt caused by the little 

 drops of grease with which — according to Landois's investiga- 

 tions ') — the glutinous layer (Oberhaiitschicht) is impregnated. 



') See: Dr. R. BlaSIUS, Ueber die Bildung, Structur und systeniatische 

 Bedeutung der Eischaale Uer ViJgel (liiaug. Diss. Gottiiigen). Leipzig, 1867, p. 19. 



