82 
Notes and Comments. 
species, differing widely from B. buteo in adult plumage, in 
plumage changes, in size, and in habits as observed in the field, 
I feel that all difficulties are overcome by regarding intermedins 
as a form of that species, intermediate between it and B . buteo. 
One point that links the two latter forms is that both are not 
truly migratory, although they move in winter. B. vulpinus 
vulpinus on the other hand is a true migrant, going right down 
through Africa. This is unfortunate in one sense, because 
African migrants are always assigned to vulpinus, while 
European birds, especially the young with brown -barred tails, 
are as often as not confused with intermedins or B. buteo. B. 
menetriesi Bogd. is a synonym of B. vulpinus vulpinus, as it 
is based on old birds which have lost most of the tail bands. 
Mr. W. Sclater (MS.) states that in Socotra B. vulpinus or 
an allied form breeds. 
A SHEFFIELD AXE. 
An amusing and lengthy correspondence is taking place in 
a Sheffield newspaper between the Curator there, and, appar- 
ently, ‘ the rest of Sheffield,’ in reference to a flint axe recently 
found in the district, which is not yet in the Sheffield Museum. 
One writer quotes a number of ‘ authorities ’ in support of 
his statement, viz., the British Museum, Messrs. G. Maynard, 
J. Reid Moir and T. Sheppard — a somewhat unexpected 
' four-in-hand.’ The correspondence shows a deplorable 
ignorance of elementary geological matters. One writer refers 
to the ‘ upper or flint -bearing ’ chalk of Yorkshire. The Upper 
Chalk of Yorkshire is flintless. In the same column, another 
writer states when Diatomacae (sic) — microscopic animals 
(sic) which exist in ‘ colonies ’ on the surface of the ocean die, 
their bodies sink, and the hard parts, which are composed of 
silica, often form into nodules by concretionary action, or 
layers, in the ooze of the sea-bed. This ooze eventually 
becomes chalk.’ ( !) The diatoms are plants, with siliceous 
skeletons ; the ooze consists largely of the hard parts of 
foraminifera, which are animals, and composed of carbonate 
of lime. 
GEOLOGICAL LITERATURE. 
The Geological Literature added to the Geological Society’s 
Library during 1920 has just been published ; this time without 
the subject index, possibly from the point of view of economy. 
We do not know who is likely to find the time to wade 
through about 3000 titles in order to ascertain what may have 
been written in 1920 relating to his particular subject, but in 
the absence of the usual subject index this will be necessary. 
The publication of a list of this kind, which is obviously in- 
tended for the use of the worker, without an index, is not only 
ridiculous, but a crime ; and we cannot sufficiently condemn 
Naturalist 
