TURDIDAE-MUSCICAPIDAE. 



in the case of eggs of which the layer referred to under 3 is coloured 

 blue or bluish green owing to the presence of oocyan, such eggs 

 are called cyanic; if only the pigment is absent (titys, of course, 

 remains out of consideration in this regard, being normally non- 

 pigmented) the eggs are called leucitic. In the case of the latter 

 eggs oocyan is also absent from the fundamental layer (mentioned 

 under 3). 



Of S. oenanthe-and M. atricapilla-eggs the outside layer is not 

 distinguished by a pigment of its own from the fundamental layer 

 (mentioned below sub 3), but the whole lime shell is coloured 

 greenish blue through oocyan. 



3. INNERMOST OR FUNDAMENTAL LIME LAYER. 



Coloured greenish blue through oocyan in the case of all the 

 species — with the exception only of Ph. titys and E. rubecula (in 

 both of which traces sometimes occur!). 



In the case of the Family Turdus — with the exception of 

 musicus — it shows a few faint rust coloured speckles or little 

 spots; in that of viscivorus, on the other hand, it is closely marked 

 with more numerous, and also larger, spots; in that of AM. luscinia, 

 C. s. Cyanecula, E. rubecula and M. grisola it is strewn with very 

 fine rusty red specks and little spots, and in that of Pr. rubetra and 

 rubicola with little yellowish spots; sometimes this pigmentation is 

 scarcely visible with the unaided eye. 



II. 



In the oological group formed by merula, torquatus, pilaris and other 

 species 1 ), two types of markings are mainly distinguishable, viz: — 



*) T. iliacus L., which I do not regard as belonging to the birds breeding 

 in the Netherlands, also belongs to this group. 



