12 OSUORN. 



types, omit lower Eocene types such as Corypliodon, and again 

 collect middle and upper Eocene types. 



Fourth : the Taeniodonta, or ancestral Edentata with enam- 

 eled teeth, are apparently truly represented in Egerkingen by 

 the Calamodoii ciiropwiis of RiTniEYER, but this tooth is quite 

 as probably in a Stv/iiioclo)i, or ^Middle Eocene (Bridger), stage 

 of development as in an older stage. 



4. Lower Eocene, Wasatch and Suessonien (Sparnacien, 

 Ypresien) truly parallel 



The SpaDiacicn of Lapp.arent is the middle substage of 

 the more comprehensive stage Soissonien (Mayer-Eymar) ; it 

 marks a continuation of the north France depression or Suesso-' 

 nien Sea (Heersien, Thanetien or Suessonien) and is character- 

 ized by marine and fluvio-marine deposits bordered to the west 

 and south by purely fresh water fluviatile or lacustrine deposits. 



Of the latter the lacustrine Lignites du Soissoiiais ( 5 metres) con- 

 tain Corvphodon ozccjiii, Pa/iroiiictis gigaiitca (Mwh^ncouri, Oise) 

 and Lophiodo/i lartcti. The Argilc p/astiqiic [^o metres) is con- 

 sidered by some mainly aerial (fide Canu), by others lacustrine 

 (Gardner, Lapparent); it commences with the Conglonicrat dc 

 Meiidon, certainly fluviatile, which contains Corypliodon anthra- 

 coidcus. 



In the London basin are the Loi^'cr Bagsliot Sands, a marine 

 formation, and below these the London Clay (166 metres), see 

 Caxu ('95, p. 54), an estuarine formation ; these together con- 

 stitute the Londinicn of Mayer-Eymar. The London Clay 

 contains a primitive species of LLyracotlicriuni, H. icporiniini, 

 a primitive Corypliodon, C. coccenns. These fossil mammals 

 would cause us to consider the London Clay as parallel with 

 the Sparnacien, but Lapparent and Canu, from the invertebrate 

 standpoint, place the London Clay in the higher level of the 

 Ypresien or Londinien. 



In the Paris Basin a fresh return of the sea deposited the 

 Sables Xunimulitiqucs du Soissonais (50 metres, Aisne) embrac- 

 ing the overlying estuarine and littoral Sables de Cnise la Motte ; 

 here Filhol ('88, p. 155) records a small Lophiodon de Cuis, 



