Families TURDIDAE and MUSCICAPIDAE. 

 (Plates 66—81). 



My comparative examination of eggshells in the case of the above 

 named Families gave me matter for the following notes. 



I. 



Counting from the exterior of the eggshell, the following layers 

 are also distinguishable in these eggshells: — 



1. GLUTINOUS LAYER. 



Occurs in the eggshells of all the species. This layer which gives 

 to the shell the so-called gloss, differing strongly qualitatively in 

 the various species, exercises by its more or less yellowish colour 

 a considerable influence on the tint of the underlying pigment, 

 which is clearly perceptible especially in the case of plain eggs 

 (phoenicurus and similar ones) after the removal, locally, of the layer. 



2. OUTSIDE LIME LAYER. 



Pigmented in the case of all the species — titys alone excepted. 

 This layer gives the so-called ground colour to the eggshell, and 

 on it the spots of the spotted species mainly occur. If it is absent 



* 



