88 On rare or unfigured Eggs of Palaarctic Birds. 



difficulty of photographing flying birds from the deck of a 

 rolling ship, often vibrating considerably, is great, and I 

 have also found that the sea makes a very bad back- 

 ground ; my most successful attempts were therefore made 

 at birds above the horizon. 



VI. — On some rare or unfigured Eggs of Pal (Paretic Birds. 

 By H. E. Dresser, F.Z.S. 

 (Plate III.) 

 When selecting specimens for my former article on the 

 eggs of certain Siberian Thrushes (Ibis, 1901, p. 445), I 

 noticed one clutch, stated to belong to Tardus dubius, which 

 differed somewhat from the rest, and on examining the 

 parent bird, which had been shot at the nest, I found it to 

 be undoubtedly a female Tardus naumanni. 



As the eggs of this species have been hitherto quite un- 

 known, I have thought it advisable to figure four out of the 

 clutch, to shew what little variation is noticeable in them 

 (see PI. III. figs. 1, 2, 3, 6). Mr. Popham informs me that 

 they were taken on the Yenesei River in 1900. He has also 

 sent me another clutch, along with the parent bird, which, 

 however, on examination proves to be a hybrid between 

 Tardus naumanni and T. dubius. It would seem, therefore, 

 that the breeding-range of these two species meets somewhere 

 about the Yenesei, and that they occasionally interbreed, as 

 is known to be the case with T. atrigularis and T. ruficollis. 



Although the Mongolian Song-Thrush (Turdus auritusVer- 

 reaux) much resembles T. muslcus, its eggs differ considerably 

 from those of that species, being, as will be seen by the 

 figures (PI. III. figs. 4, 5), much more of the Misletoe- 

 Thrush type. This Thrush inhabits Mongolia and Northern 

 China. Prjevalsky found two nests in Kan-su in the middle 

 of May — one on a broken tree-stump, and the other on the 

 branch of a willow, about seven feet from the ground. One 

 of the eggs now figured was obtained by Mr. Berezovski near 

 Mindjeon, in Kan-su, while the other is from the collection 

 ot Mr. Goebel of St. Petersburg. 



