2 Mr. Owen on some Fossil Teeth from Suffolk. 



midway into a small crateriform tubercle in the teeth of the 

 Hyracotherium leporinum, but preserves its trenchant cha- 

 racter in the Hyrac. Cuniculus, even in molars which have the 

 larger tubercles worn down. 



The premolar, or false molar, in the series of detached 

 teeth from Kyson, which is either the third or fourth, pre- 

 sents the same complication of the crown which distinguishes 

 the Hyracotherium from the Cheer opotamus, but with 

 the same minor modification which distinguishes the 3 

 true molars of the Kyson species from those of the 

 Hyrac. leporinum of Heme Bay ; i. e. the two ridges 

 which converge from the two outer tubercles towards 4 ffji 

 the internal tubercle are not developed midway into W 

 the small excavated tubercle, as in the Hyrac. leporinum, fig. 3, 

 but are simple, as in fig. 4. 



The disparity of size between the true and false molars ap- 

 pears to be greater in the Hyrac. Cuniculus than in the Hyrac. 

 leporinum. This discovery of a second species of the genus 

 Hyracotherium, which, hitherto, has been found only in the 

 London clay, tends to place beyond doubt the equivalency of 

 the Kyson sand, underlying the red crag, with the Eocene 

 deposits at the estuary of the Thames, and corroborates the 

 inference deducible from the previously described mammalian, 

 ornithic and ophidian remains of the London clay, that it was 

 deposited in the near neighbourhood of dry land. 



I may add, that the collection of teeth and other small or- 

 ganic fragments from the Kyson clay, which included the 

 molars of the small extinct Pachyderm above described, like- 

 wise included several vertebrae of a serpent, agreeing in every 

 respect, save size, with those of the Palceophis toliapicus, re- 

 cently described by me, from the Isle of Sheppey. The Ky- 

 son serpent must have been about seven feet in length : that 

 of Sheppey exceeded ten feet ; but I have lately had submitted 

 to me for examination, by my friend Mr. Dixon of Worthing, 

 vertebrae of a distinct species of Palceophis from the Eocene 

 clay at Bracklesham, corresponding in size with those of a 

 Boa Constrictor of upwards of twenty feet in length. 



Fig. 1 . Grinding surface of the crown of the last true molar, right side, up- 

 per jaw, of Hyracotherium leporinum, from Heme Bay. 



Fig. 2. Ditto, of the corresponding molar of the Hyracotherium, Cuniculus, 

 from Kyson. 



Fig. 3. Grinding surface of the last false molar (the fourth counting back- 

 wards), left side, upper jaw, of Hyracotherium leporinum, from Heme 

 Bay. 



Fig. 4. Ditto, of the corresponding tooth of the Hyracotherium 

 Cuniculus, from Kyson. 



Fig. 5. Last true molar, left side, upper jaw, of Hyracotherium ' 

 Cuniculus, from Kyson. 



