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The British Association » 
rocks at an accessible depth under London has proved true. 
Professor Prestwich, from a consideration of the French and 
Belgian coal fields, inclines to the belief that in the district 
north of London carboniferous strata may be found. 
In the department of theoretical geology, the president 
called attention to some experiments by M. Daubree, in 
which he has attempted to reproduce on a small scale 
various geological phenomena, such as faulting, cleavage, 
jointing, and the elevation of mountain chains. 
With regard to recent progress in palaeontology, he re- 
ferred to the magnificent discoveries in North America, 
which are principally due to the researches of Professors 
Marsh, Leidy, and Cope. The dicer athevium, a rhinoceros 
with two horns placed transversely, and the dinoceras, some- 
what allied to the elephant, but with six horns, arranged in 
pairs, were, he said, as marvellous as some of the beasts 
seen by Sir John Maundeville on his travels, or heard of by 
Pliny. But perhaps the most remarkable series of remains 
ever discovered were those which so completely link the 
existing horse with the eohippus and orohippus, and still 
farther extend the pedigree of the genus equus , which had 
already been some years ago so ably traced by Professor 
Huxley. 
Of these American discoveries, as well as those made in 
the tertiary beds of Europe, M. Albert Gaudry has largely 
availed himself in his recent beautiful volume on the links 
in the animal world in geological times, a work which 
will long be a text-book on the inter-relation of different 
orders, genera, and species. 
The president concluded by remarking that Professor 
Marsh has largely added to our knowledge of early forms of 
birds with teeth. The tertiary Odontoptevyx toliapicus from 
'Sheppey, described by Professor Owen, seems rather to be 
endowed with bony tooth-like processes in the jaw, than 
adtual teeth, and the head of the argillornis from the same 
locality is at present unknown. But the hesperornis and 
ichthyovnis from the cretaceous beds of America possess 
veritable teeth, in the one case set in a long groove in the 
jaw, and in the other in adtual sockets. Such intermediate, 
or, as Professor Huxley would term them, intercalary forms, 
tend materially to bridge over the gap which at first sight 
appears to exist between reptiles and birds, but which to 
many palaeontologists was far from being impassable, long 
before the discoveries just mentioned. The amphicoelous 
character of the vertebrae of ichthyovnis presents another 
most remarkable peculiarity, which is also of high signific- 
