TURDIDAE-MUSCICAPIDAE. 



1. a more or less cloudy marking spread uniformly over the 

 whole surface of the shell, only faintly visible against the ground 

 colour; 



2. clearly pronounced spots of varying size, sharply separated 

 from one another. 



Viscivorus and musicus stand towards the merula-gwup as indi- 

 vidually well specialised species, possessing only a few more or less 

 convergent aberrations in common with that group (e. g., eggs that 

 are plain or marked with a single spot, and frequently cyanic). 



In the case of E. rubecula- and M. grisola-eggs, the two above 

 indicated types of the merula-gwup, respectively, are found as the 

 most commonly occurring marking. 



The two principal types of the cyanecula-egg unite this species 

 oologically on the one side with Aed. luscinia, on the other with 

 Pr. rubicola. 



The shells of rubetra-eggs, when compared, e. g., with those of 

 rubicola, distinguish themselves by a more massive nature and a 

 stronger gloss, and in both respects most resemble eggs of luscinia. 



Ph. phoenicurus, titys (with weak cyanic transitions towards 

 phoenicurus), S. oenanthe (with white aberrations), and M. atricapilla 

 (deviating from grisola also in manner of nesting) are oologically 

 characterized by a common softness of the eggshell peculiar to them. 

 Accentor modularis l ), which several authors class with the Turdidae, 

 may also be included in this oological group. 



TURDUS MERULA L. 



Dr. Thienemann 2 ), speaking of the ground colour, says, among 

 other matters: — „Die lebhaftesten habe ich aus Holland und 



*) See XIV. Family. 



2 ) 1. c. page 280, 2nd no te. 



