5 
Siberian form, “ P. sibiricus, forma typica, inter Amga et Aldan, 16 Apr. (Sibir. Orient. 60° lat.),” 
by Middendorff (0. ¢.) is said to be exactly similar in colour to the former “ without reddish brown 
on the sides of the body,” but much less in size. “ Wing 55 millims., tail 65 millims.” ‘To this 
latter form doubtless belongs Parus cinereus lenensis, “vertice fusco,’ which, Pallas (Zoogr. i. 
p- 598, nota sub P. palustri) states, was seen by Gmelin, senior, on the Lena river, not far from 
where Middendorff found it more than one hundred years afterwards. Further to the eastward, 
at Ochotsk and Kamschatka, this bird is replaced by another species with a brown (not a black) 
head, Parus rufescens, Audubon,=P. ferrugineus (Lundahl, /. c. fig. opt.), which is also found in 
the north-western part of North America. It is richer-coloured, has the back and sides of the 
body dark reddish brown, and is less in size. ‘ Wing 62 to 68, tail about 52 millims.” 
We happen to have in our collection an example of a Titmouse from the southern part of 
Lake Baikal, which formed part of a series of specimens sent to our friend M. Jules Verreaux by 
Dr. Taczanowsky ; and all these specimens agreed inter se, and were not the same as P. cinctus 
of Europe. ‘They differ in being clearer grey, with the head almost uniform with the back, the 
white on the neck and breast much purer, and far less rusty on the flanks; the wing and outer 
tail-feathers are also more plainly edged with white. In fact this species, which we propose to 
call Parus grisescens, seems to bear the same relation to P. sitiricus that P. borealis does to 
P. palustris, and we feel confident that further research will result in the discovery of differences 
in the habitats and economy of the two species. P. grisescens is doubtless the bird procured near 
_ Peking by Pere David, unless, indeed, the small form of P. stbiricus referred to above by 
Professor Sundevall is the bird intended. 
In the preparation of the above article we have examined the following specimens :— 
E Mus. Sharpe and Dresser. 
a. Quickjock, Lapland (A. Dahlberg). 6. Ropathjera, Sweden (Meves). c¢. Norway (Collett). d. Southern 
part of Lake Baikal (type of P. grisescens). 
E Mus. H. B. Tristram. 
a. Siberia (Verreauz). 
