350 Notes and Comments. 
noted in general terms by Louis Agassiz. The dominant 
Silurian fishes seem to represent a stage before the interior 
visceral arches had become completely differentiated into jaws, 
and before paired fins had been developed. The subsequent 
successive stages are marked by (1) the acquisition of normal 
jaws and paired fins ; (2) the addition of a bony exo-skeleton ; 
(3) the supersession of paddles by purely dermal expansions as 
fins ; (4) the abbreviation of the primitive tail and the correla- 
tion of the dermal rays with the endoskeletal supports in the 
dorsal and anal fins ; and (5) the completion of the ossification 
of the endoskeleton. The directions of specialization in each 
of these grades, at successive periods, are essentially similar, 
but at every advance more variation becomes possible, and the 
diversity among Tertiary and recent teleostean fishes is very 
much greater than in the groups of any earlier period. Whether 
these advances have taken place simultaneously in different 
parts of the world, or whether they have occurred locally and 
then spread by migration, is still a difficult question. This 
and kindred problems can only be discussed by comparing 
the paleontology of the fishes with that of other animals 
which have been similarly studied. 
GRIME’S GRAVES. 
We have received an admirable ‘ Report on the Excavations 
at Grime’s Graves, Weeting, Norfolk,’ March-May, 1914, 255 
pp., price 5s. net. A committee was formed for the purpose of 
systematic excavations of the remarkable structures known as 
Grime’s Graves, and whatever may be one’s views as to the 
origin of these extraordinary structures, there can be no 
question that the present report supplies a mass of facts which 
should be carefully studied by the serious student. The 
Society has also illustrated the report by thirty plates and 
nearly a hundred illustrations in the text. There is a dis- 
cussion as to the age of the pits. We are permitted to repro- 
duce a remarkable photograph of an extraordinary number of 
picks of red deer antlers (erroneously called ‘horns’) found 
during the excavations. Many of the subscribing institutions 
now have examples of these in their collections. 
: On 
BRITISH ASSOCIATION NOTES; 
FAUNA OF THE LIMESTONE BEDS 
Mr. Henry Day put forward some observations on a collect- 
ion of some three hundred species of Carboniferous Limestone 
fossils from the localities Treak Cliff and Peakshill, Castleton, 
and embracing about one hundred species of brachiopods and 
corals. The beds at both places may be referred to the * brachio- 
pod beds’ of Sibly (‘Q.J.G.S. 1908’), and what are allocated 
by him to sub-zone D?—the Lonsdalia sub-zone. The present 
Naturalist, 
