20 OSBORN. 



The age of these various deposits is a very important matter. 

 For reasons given above and below certain of these deposits ap- 

 pear to have overlapped or extended through one or more periods 

 of regular stratigraphic deposition as follows : 



Egerkingen (Canton Vaud) Middle to Upper Eocene 

 inclusive. 



Lissieu, Middle to Upper Eocene inclusive. 



Fronstetten (Swabian Alps), Mainly Upper Eocene. 



Heidenheim (Mittelfranken), " " 



Mauremont (Canton Vaud) " " 



Oerlinger Thai. u. Eselsberg, Ulm, Upper Eocene. 



Quercy, Caylux, Mouillac, Phosphorites, Upper Eocene 

 to Middle Oligocene. 

 The Phosphorites du Quercy, the most extensive and 

 famous fissure deposits of this kind, occur in Jurassic calcareous 

 fissures of 3 to 6 metres in width and 35 metres in length. The 

 matrix is a phosphate of lime probabl)' of mineral spring origin 

 (FiLHOL, '77, p. 1—27). The fauna enjoyed a warm and moist 

 climate. Filhol believ-es that death was caused by asphyxia- 

 tion, due to poisonous vapors arising from hot springs, man}' 

 skeletons being found complete and showing no marks of teeth. 

 In contrast with Quercy, which contains a fauna of extraordi- 

 nary richness, beauty and completeness, Egerkingen and Lis- 

 sieu have yielded merely isolated teeth. 



The Quercy fauna according to Filhol predominates in 

 Upper Eocene or Gypsc types. The Phosphorite rhinoceroses 

 have by some authors and in many museums been referred to 

 A. Icinanciisc and A. miiuitimi, both of which are Upper Oligo- 

 cene or Aquitanean species — tliis is an error ; the two rhinocer- 

 oses which this formation contains are probably the Rotizo- 

 thcriuni vchniuuni Avmard, found also in Ronzon, and another 

 species much simpler than the Aquitanean DiccratJicruim juiun- 

 tuni Cuv. {R. plcuroceros Duvernoy), of Moissac. This small 

 species has simple upper premolars ; it either belongs to A. 

 gaiidryi Rames, or represents a distinct species. These facts 

 with the tables published by Filhol ('77) show that the Quercy 

 deposition probably terminated in the lower or Middle Oligocene. 



