CATALOGUE OF BIllDS. 177 



it appears to be more partial to the lochs that lie in 

 wild, hilly districts, preferring those with rocky 

 islands, on which it rears its young. 



I have occasionally seen as many as from fifteen to 

 twenty fine old birds at one time on a single loch 

 during the summer months, diving, splashing, and 

 screaming, and now and then pursuing one another, 

 both above and below the surface. Whether these 

 were birds that had been robbed of their eggs or young, 

 or had only gathered together for the sake of company, 

 I can form no idea, as possibly on my next visit to the 

 same loch, but a single pair would be visible. 



At times, when crossing the hills, I have noticed 

 as many as eight or ten flying together ; on such 

 occasions they keep in a straight line, at regular 

 intervals, one behind the other. 



The newly-hatched young are covered with black 

 down; like all waterfowl, they take to their natural 

 element as soon as they leave the shell. 



The specimens in the case were obtained in the 

 west of Ross-shire, in May, 1868. 



BLACK-THKO ATED DIVER.— (Immature.) 



Case 226. 



Immature birds of this species are not unfrequently 

 met with during the winter in the south of England, 

 at times being found on both fresh and salt water. 



The specimen in the case was shot on Heigham 

 Sounds, in Norfolk, in February, 1871. 



K 



