2. The Torrejon and Thanétien (Cernaysien) nearly Parallel The oldest fossil mammal beds of Europe are the fluvio-marine Glauconie de la Fère (Aisne, 6 metres), containing Arctocyon primavus, equivalent to the marine Sables-de-Bracheux, also resting upon the Cretaceous which is immediately overlaid by the lacustrine Calcaires et sables de Rilly (38 metres). These together constitute the Thanétien (LAPPARENT, '85), with which the purely fresh-water Cernaysien (LEMOINE) beds in the vicinity of Rheims are closely parallel.

The Cernaysien has been almost universally paralleled with the Puerco, but many years ago, while studying the Cernaysien fauna of Rheims, with the kind aid of the late Doctor VICTOR LEMOINE, I reached the conclusion that it was more recent than Puerco (OSBORN, '90, pp. 51-62). This conclusion is now confirmed by the separation (WORTMAN and MATTHEW, '99, p. 28) of the true Puerco fauna underlying the Torrejon fauna. The Torrejon agrees closely with the Cernaysien, so far as we can judge from evidence which awaits a more exact study of the Cernaysien fauna than we have yet enjoyed.

a. MULTITUBERCULATES. It is especially interesting to compare the number of grooves and tubercles upon the Neoplagiaulax (Cernaysien) and Ptilodus (Torrejon) fourth premolars and first lower molars, as indicating a similar age.

b. Among the RODENTS OF PRIMATES (for the systematic position of these animals is not definitely known, see SCHLOSSER and MATTHEW) compare Protoadapis (Cernaysien), dentition 2-1-3-3, and Plesiadapis with its reduced dentition, simple molar type and enlarged incisors, with Indrodon (Torrejon) (? 1. 3. 3).

c. CREODONTS. Of the Mesonychida, Hyænodictis (Cernaysien) is a little more modern than Dissacus (Torrejon) in its lower molars. Of the Arctocyonida, Arctocyon gervaisii (Cernaysien) and Arctocyon (Clanodon) corrugatus (Torrejon) are to be compared.

d. UNGULATES. As hypothetically ancestral to the Ancylopoda, Pleuraspidotherium (Cernaysien) is in an earlier stage

than Meniscotherium (Wasatch) which it somewhat resembles in teeth, skull and skeleton.

The fact that neither primitive UNGULATES (Condylarthra and Amblypoda) nor EDENTATA have been found in the Thanétien or Cernaysien beds, together with their absence in the Suessonien and later periods in the Palearctic region, lends some probability to the hypothesis that Condylarthra, Amblypoda and Edentata were exclusively Nearctic during the lower Eocene. On the other hand the Cernaysien beds may present a very imperfect picture of life in France during this period.

3. Egerkingen Beds more recent than Puerco, Torrejon or Wasatch

Nor is the above probability lessened by the testimony of Egerkingen which has been widely accepted as proving the existence of the Condylarthra in Europe and as in part a very old fauna.

The suppositions of Rütimeyer ('88), already questioned by SCHLOSSER ('95), that the older portion of the famous fissure fauna of Egerkingen is of Puerco age and that it contains Condylarthra are rendered improbable by the following considerations.

FIRST by my examination of the teeth referred to Euprotogonia, Periptychus and Phenacodus in the Egerkingen collection, which fails to sustain Professor RÜTIMEYER'S identifications. Egerkingen is rich in small Eocene Primates; it is possible that the types of the supposed Condylarthra correspond with the larger Bridger or Middle Eocene American monkeys such as Notharctus, Tomitherium (COPE) Telmatolestes, Limnotherium (MARSH) which are astonishingly ungulate in appearance.

SECOND: I have certainly seen similar primate teeth in Professor DEPÉRET's collection from Lissieu; this is also a fissure fauna and of similar age to Egerkingen.

THIRD because of the absence in Egerkingen of many typical lower Eocene or Suessonien types and the abundant presence of typical middle and upper Eocene types. It is improbable that a Jurassic fissure would accumulate basal Eocene

types, omit lower Eocene types such as Coryphodon, and again collect middle and upper Eocene types.

FOURTH the Tæniodonta, or ancestral Edentata with enameled teeth, are apparently truly represented in Egerkingen by the Calamodon europæus of RÜTIMEYER, but this tooth is quite as probably in a Stylinodon, or Middle Eocene (Bridger), stage of development as in an older stage.

4. Lower Eocene, Wasatch and Suessonien (Sparnacien,

Yprésien) truly parallel

The Sparnacion of LAPPARENT is the middle substage of the more comprehensive stage Soissonien (MAYER-EYMAR); it marks a continuation of the north France depression or Suessonien Sea (Heersien, Thanétien or Suessonien) and is characterized 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 Soissonais (5 metres) contain Coryphodon owenii, Palæonictis gigantea (Muirancourt, Oise) and Lophiodon larteti. The Argile plastique (50 metres) is considered by some mainly aërial (fide CANU), by others lacustrine (GARDNER, LAPPARENT); it commences with the Conglomerat de Meudon, certainly fluviatile, which contains Coryphodon anthracoideus.

In the London basin are the Lower Bagshot Sands, a marine formation, and below these the London Clay (166 metres), see CANU ('95, p. 54), an estuarine formation; these together constitute the Londinien of MAYER-EYMAR. The London Clay contains a primitive species of Hyracotherium, H. leporinum, a primitive Coryphodon, C. coconus. 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 Yprésien or Londinien.

In the Paris Basin a fresh return of the sea deposited the Sables Nummulitiques du Soissonais (50 metres, Aisne) embracing the overlying estuarine and littoral Sables de Cuise la Motte; here FILHOL ('88, p. 155) records a small Lophiodon de Cuis,

this would correspond with Heptodon, the first of the American Lophiodontida. GAUDRY ('98, p. 302) parallels with these beds. the freshwater Sables Agéiens (D'EPERNAY), Étage Agéien, LEMOINE, the mammalian fauna of which has been described by LEMOINE as containing Lophiodon and Pachynolophus; but this fauna belongs on a higher level, as in fact GAUDRY himself inti

mates.

The parallel between the Wasatch and the Suessonien of France was first recognized by MARSH in describing Coryphodon. In the meantime vast additions have been made to our knowledge of the Wasatch fauna and practically nothing to that of the Suessonien. Although we know only a fraction of the life of the period, there certainly existed at this time in Europe the successors to certain Cernaysien genera which are represented by descendants in the Upper Eocene.

The three known genera common to both countries, namely, Coryphodon, Hyracotherium and Palæonictis present close structural parallels.

Filhol records Lophiodon larteti of the Lignites du Soissonais as an ancestor of the true heavy bodied Lophiodontinæ, whereas in the Wasatch we find Heptodon belonging to the light bodied Lophiodonts of the "Helaletes-Colodon " line which subsequently appears in Europe. Platycharops, mistakenly compared with Esthonyx by LYDEKKER has no parallel in America unless among the Arctocyonide. GERVAIS ('59) mentions a rodent-like type of incisor from the Suessonien, but this has not to my knowledge been subsequently described.

5. Fissure Formations, Egerkingen and Lissieu, younger than the Wasatch

These formations both represent the remains of animals slowly accumulated in fissures of Jurassic age. The Lissieu fauna is of approximately the same Middle and Upper Eocene duration. As above stated the Egerkingen composite fauna almost certainly does not contain types as old as those of the Wasatch. There is one important exception: the Proviverra typica of Egerkingen is in the same stage of development as the Sinopa (Sty

polophus) viverrina of the Wasatch, while RÜTIMEYER'S supposed Stypolophus does agree with the Sinopa brevicalcarata of the Bridger. Notwithstanding these facts, in the absence of Coryphodon, Palæonictis and other typical Wasatch and Suessonien forms, the greatest age which can be positively assigned to the beginning of these fissure formations is the lower portion of the Middle Eocene.

6. Middle Eocene, Lutétien, apparently parallel with the Wind River Fauna

Constituting the base of the greater Parisien stage, the Lutétien substage, first, marks the advance of the sea beyond its Suessonien limits southward around Paris, and to the west and north into Belgium; second, it marks the appearance of fossil mammal deposits in the south of France, in Switzerland (Helvetien Canal), and in Alsace.

The Calcaire grossier beds (45 metres) are entirely marine in their lower strata (Calc. gros, moyen. et infér.) but become freshwater or fluviatile at the summit (Calc. gros. supér.) where they contain Lophiodon and many other ungulates.

Parallel with these beds are those of the Gres d'Issel (Aude, 24 metres) fully studied by FILHOL ('88); of Argenton (Indre); of the Argiles à lignites, or Agéin (Rheims) explored by Dr. Lemoine, of Bracklesham (England). Certain types of Buchsweiler, Alsace, seem to be somewhat more recent. Finally our knowledge of the mammals of this stage is greatly enriched by the older portions of the fissure deposits of Egerkingen (Vaud) and of Lissieu, near Lyons.

This fauna has been hitherto paralleled with that of our great Middle Eocene deposits of the Bridger; we shall see that it only corresponds with a section of the upper Wind River or the Lower Bridger Lake deposits of the Rocky Mountains.

Characteristics: FILHOL ('88, p. 1, 75), in his conclusion upon the Issel fauna, speaks doubtfully of the presence of a large Creodont, as Palonictis gigantea.

This is the continuation of the reign of Lophiodon, a type predominant in number and variety.