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POPULAR SCIENCE REVIEW. 
500 metres iu thickness and belonging to the Trias. The earliest Jurassic 
beds belong to the Middle Lias ; these are followed by unfossiliferous lime- 
stones (sometimes dolomitic) ; and the uppermost Mesozoic deposits are whitish 
limestones with Neocomian fossils. All these strata are tilted at a high 
angle, and against them, as above stated, abut the Middle Miocene lime- 
stones which form the greater part of the southern region. Recent cal- 
careous deposits containing Hdix vei'miculans and some fragments of marine 
fossils attain to a considerable extension, and rest indifferently upon the 
Miocene and older beds, indicating a great descending movement at the time 
of their formation. 
In Majorca the oldest deposits are red sandstones (Trias), and these are met 
with only at one spot on the coast. Above these there is the same succes- 
sion of formations as in Minorca ; but the Middle Lias fossils are only found 
in a few localities. Above this are about 400 metres of limestones, generally 
uufossiliferous, which probably represent a great part of the Jurassic 
strata ; at the Puiz de Lope ammonites occur which seem to indicate the 
presence of the Oxfordian ; and the series is crowned by limestones con- 
taining Cephalopoda, which indicate the horizon of Ammonites trcinsitorius. 
The Neocomian is greatly developed, and contains a fine fauna. If the older 
beds are wanting, the Tertiaries, on the contrary, are much better developed 
than in Minorca. The lowest stage of these is a lacustrine limestone with 
beds of lignite at its base in some places, which the author regards as of 
Lower Eocene age ; it was thought to be supra-nummulitic by Haime, but 
is overlain by the Nummulitic limestones. The lake in which these deposits 
were thrown down was more than 80 kilometres in its longest diameter. 
The Stonesfield Mammals . — It has long been known that in the so-called 
“ Stonesfield slate ” of Oxfordshire, a part of the Lower Oolite formation, the 
remains of mammalia occur ; in fact, four species, belonging to three genera, 
are recorded by Professor Owen. Of these, the most ancient mammals after 
the Microlestes of the Keuper of Wiirttemberg, which is known only from 
teeth, the only traces hitherto described have been the lower jaws. Pro- 
fessor Seeley has announced to the Geological Society (February 21, 1879) 
his discovery, in slabs of Stonesfield slate which have been preserved for 
many years in the British Museum, of two small bones, which, on examina- 
tion, were found to present mammalian characters. These are a femur and 
a humerus ; and as they nearly correspond in size, and there is no evidence 
to the contrary, Professor Seeley preferred to regard them provisionally as 
belonging to the same species, and from their characters he was inclined to 
associate them with the jaw described under the name of Phascolotherium. 
They are considered by him to indicate a special, probably insectivorous, 
monotreme type, with marsupial tendencies, such as, on the hypothesis of 
evolution, might well be supposed to occur early in the history of the mam- 
malia. It is to be hoped that the detection of these interesting remains 
may lead to a careful examination of the slabs from Stonesfield which exist 
in many museums, and that the search may be successful. 
Conodonts . — The curious minute fossils described by Pander under the 
name of Conodonts, and regarded by him as probably the teeth of fishes of 
very low organisation, have been detected in great abundance by Mr. G. J. 
Ilinde in rocks of the Cliazy and Cincinnati groups of the Cambro-Silurian, 
