566 NATURAL SCIENCE. oct.. 



lime contained in fossil bones of the primary and secondary epochs. 

 There is much less fluoride in those of the tertiary epoch, of the 

 quarternary, and especially of modern times." He further applies his 

 method to determining whether certain human bones found with those 

 of extinct animals are really contemporaneous or are of later origin, 

 and have been introduced into the deposits where they now occur. A 

 human tibia discovered by M. Riviere in association with bones of 

 animals was specially submitted to M. Carnot for examination ; and 

 analysis proved that this tibia contained only the same percentage of 

 fluoride as a recent human bone, while the associated animal remains 

 yielded seven to nine times as much fluoride as their recent analogues. 

 Hence, concludes M. Carnot, the human tibia in question belongs to 

 a later period than the other fossils with which it was found — a result 

 in which M. Riviere acquiesces on other grounds. 



The Miocene Mammals of France. 



It is not a little remarkable that the wonderful discoveries of 

 Tertiary mammals made during the last twenty years in the United 

 States have been paralleled by a great advance during the same 

 period in our knowledge of the fossil mammals of Europe, and more 

 especially France. As our readers may be aware, it is within that 

 space of time that we have become acquainted wilh the marvellous 

 fauna of the Phosphorite beds of Central France through the labours 

 of Dr. H. Filhol, while our knowledge of the mammals of the Oligo- 

 cene beds of St. Gerand-le-Puy, and of the Miocene of Sansan in 

 the Gers, has been greatly augmented. It is true, indeed, that the 

 extinct European mammals of these horizons do not include many of 

 the strange forms characterising the equivalent beds on the other 

 side of the Atlantic ; but they comprise, on the other hand, many 

 types which are quite unknown there, and their importance to the 

 palaeontologist and evolutionist can scarcely be overestimated. 



Among the faunas of which our knowledge has advanced with 

 such rapid strides during the last few years is that of the village of 

 La Grive-St.-Alban, in the Isere, belonging to the upper division of 

 the Miocene period. The mammals of this fauna were first brought 

 to notice by Dr. Jourdan in the year 1861, and new forms from the 

 same beds were subsequently described by MM. Filhol, Chantre, and 

 Depere't; but it has been reserved for the writer last mentioned to 

 make us acquainted with the full extent and importance of the fauna 

 in question. This task has been completed (so far as present 

 materials permit) in a memoir just published by Dr. C. Deperet,' 

 which treats not only of the mammals of La Grive, but likewise of 

 those from other gisements in the Rhone basin ; and when we mention 



1 " La Faune de Mammiferes Miocenes de La Grive-St.-Alban (Isere) et de 

 quelques autres Localiles du Ba<;sin du Rhone." Aichiv. Mus. Lyon, vol. v., pp. 

 1-94, pis. i.-iv. 



