THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



No. 48. SEPTEMBER 1841. 



I. — Description of some Molar Teeth from the Eocene Sand 

 at Kyson in Suffolk, indicative of a new Species of Hyra- 

 cotherium (Hyr. Cuniculus). By Richard Owen, Esq., 

 F.R.S., &c. 



IN the Eocene sand underlying the red crag at Kingston or 

 Kyson in Suffolk, from which the remains of Quadrumana, 

 Chiroptera, and Marsupialia have already been obtained*, 

 Mr. Colchester, the discoverer of those mammalian remains, 

 has recently transmitted to me through my friend Mr. Lyell 

 a second collection of fossils, including the teeth of small 

 mammalian animals, some of which are referable to the small 

 Pachydermal extinct genus Hyracotherium, established on a 

 nearly entire cranium obtained by Mr. Richardson from the 

 London clay near Heme Bay, in 1839f. 



The teeth from Kyson are three true molars and one of the 

 false molars, all belonging to the upper jaw. The crowns of 

 the true molars present the same shortness in vertical extent, 

 the same inequilateral, four-sided, transverse section, and 

 nearly the same structure, as in Hyracotherium leporinum ; 

 the grinding surface being raised into four obtuse pyramidal 

 cusps, and surrounded by a well-developed ridge, produced at 

 the anterior and outer angle of the crown into a fifth small cusp. 



These teeth are, however, of smaller size, as will be seen 

 by the subjoined figures of a corresponding molar 

 from the Hyrac. leporinum, fig. 1, and Hyrac. Cu- 

 niculus, fig. 2. The true molars of these two spe- 

 cies further differ in a point not explicable on the 

 supposition of their having belonged to a smaller 

 individual or variety, for the ridge which passes 

 transversely from the inner to the outer cusp is developed 



* See Annals of Natural History, vol. iv. No. 23, Nov. 1839. 

 t Geological Transactions, 2nd Series, vol. vi. p. 203. 



Ann. fy Mag. N. Hist. Vol. viii. B 



