H. Lydeliher — On Fossil Mammalia. 



69 



however, the need of caution in founding new species merely on the 

 presence or absence of a diastema. Under these circumstances it 

 appears desirable to await additional specimens before deciding 

 whether the present specimens should be regarded as a new species, 

 or merely as a well-marked variety. The name Bravardi, either as 

 a specific, or a varietal one, may eventually be appropriately applied 

 to this form. 



Anthracotheridm Gresslti (H. v. Meyer). 

 Ffom the Seadon beds of Sordioell. 



In the year 1846, the late Hermann von Meyer (Neues Jahrbuch, 

 p. 471) briefly described some mammalian teeth from the siderolithes 

 of Egerking"n, Canton Solothurn, Switzerland, under the name of 

 Tapinodon Gresslyi. In 1862 Professor Riitimeyer (Denkschr. schw. 

 nat. Ges., vol. xix. art. 3, p. 70, pi. v. figs. 64-67), described and 

 figured the three associated upper true molars, and the second and 

 third lower true molars, of a small mammal from the same deposits, 

 which he identified with Meyer's Tapinodon Gresslyi, but referred to 

 the genus Hyopotamus, under the name of H. Gresslyi (Myr.). 



Among the collection made by the late Marchioness of Hastings 

 from the Headon beds of Hordwell, Hampshire, and now in the 

 British Museum, there is the cranium (No. 29,851), and a mandible 

 (No. 29,713), probably belonging to the same individul, and certainly 

 to the same species, of a small mammal, the teeth of which agree 

 precisely with those figured by Riitimeyer under the name of 

 Hyopotamus Gresslyi. The Hordwell specimens may, therefore, be 

 referred to that species. 



Fig. 5. Jnthracotherium Gresslyi (Meyer). Tbe left half of the palate and the 

 upper cheek-dentition ; from the upper Eocene of Hordwell. (B.M. No. 29,851.) i- 



The Hordwell cranium has been so much crushed and broken 

 that it has not been deemed desirable to give a figure of its upper 

 surface; but the left side of the inferior surface and the cheek- 

 dentition are figured in the accompanying woodcut (Fig. 5). The 

 cheek-series comprises six approximated teeth, and one tooth (P^iJ) 



