INTRODUCTION. IX 



French Ccenoiherium commune, are confirmatory of the foregoing 

 views, and indicate (as might have been expected) that the Tertiary 

 faunas of the German and French areas contain a large number of 

 forms in common. 



Considerable difficulty has been experienced in these and other 

 instances in regard to the generic and specific names which should 

 be adopted, as German writers almost invariably employ terms of 

 German origin, while French authors have an equal partiality for 

 those given by their own countrymen. In cases where the first 

 published notice is clear and distinctive, the rule of priority has been 

 followed ; but there are many instances (notably those of H. von 

 Meyer) where the original notice is so vague that it is practically 

 useless, and in such instances the choice has fallen on the name 

 which appears to have obtained most general acceptation, or was the 

 first to be distinctly defined. 



As in the First Part, the circumstance that specimens apparently 

 indistinguishable from one another were obtained from different 

 geological horizons has not of itself been considered a bar to their 

 reference to the same species, although a provisional reservation has 

 been adopted in some such cases. 



The genus Anoplotherium (as here employed) is one of peculiar 

 difficulty in regard to the association of the jaws and limb-bones of 

 the various species ; and no very definite conclusion has been arrived 

 at. The Quercy astragalus mentioned in the Addenda (page 316) 

 has somewhat increased the complexity of the problem ; but if the 

 form to which it belonged be really distinct from the so-called 

 EurytJierium latipes, yet, in the absence of any distinction in dental 

 characters, it would seem inadvisable that it should receive a distinct 

 name. The following Collections are additional to those enumerated 

 in Part I. pp. xi, xii : — 



Bowerbank Collection. — Purchased in 1865 from the late Dr. J. S. 

 Bowerbank, F.P.S., of Highbury. 



Layton Collection. — Consists mainly of specimens dredged off 

 Happisburgh, Norfolk, and was purchased from the Eev. John 

 Layton, of that place, in 1858. 



Sloane Collection. — Purchased from the executors of Sir Hans 

 Sioane, of Chelsea, about 1754. 



Wigham Collection. — Collected by Mr. Wigham, of Norwich, and 

 purchased in 1859 from Mr. T. G. Bayfield, of the same town. 



My thanks are again due to Mr. W. Dalies, F.G.S., not only for 



