HY^NODONIIDJE. 25 



cimen agrees exactly with the corresponding portion of 

 the last specimen. Purchased, 1884. 



M. 1669. Fragment of the right ramus of the mandible, containing 

 the three true molars, the last two premolars, and the 

 alveolus of the canine ; from the Upper Eocene of Caylux. 

 This specimen appears to agree very closely with the 

 mandible figured by P. Gervais in the ' Zoologie et 

 Paleontologie Franchises,' 2nd ed. pi. xxiv. fig. 11. The 

 space occupied by the last five cheek-teeth is 0,057, and 

 the interval between the alveolus of the canine and the 

 hinder border of m. 3 is 0,070. Purchased, 1884. 



Hyaenodon minor, P. Gervais 1 . 



This species is larger than Hycenodon brachyrhynchus, from 

 which it is distinguished by its relatively longer mandible, larger 

 canine, and smaller last lower true molar. The type specimen was 

 obtained from the Upper Eocene near Alais (Gard), France. 



Hab. Europe. 



29752. The mandible of a very aged individual ; from the Headon 

 beds (Upper Eocene) of Hordwell, Hampshire. The teeth 

 are very much worn, the crowns of most of the true molars 

 having completely disappeared ; the incisors and the first 

 premolar are wanting, and the crown of the left canine is 

 broken off. The specimen seems to agree precisely with 

 the type mandible figured by P. Gervais in the Zool. et Pal. 

 Franchises, 2nd ed. pi. xxv. fig. 9. It differs from the 

 mandible of H. brachyrhynchus by its more elongated 

 form, and is considerably larger than that of H. compressus, 

 FilhoP, although somewhat similar in form. It is on the 

 evidence of this specimen (which has been already noticed 

 by the present writer in the Geol. Mag. dec. 3, vol. i. 

 p. 444) that the occurrence of Hycenodon in the Hamp- 

 shire basin 3 is recorded in the Quart. Journ. Geol. Soc. 

 vol. xxxix. p. 571. The interval between the canine and 

 the hinder border of m73 is 0,076. 



Hastings Collection. Purchased, 1855. 



1 Zool. et Pal. Frangaises, 1st ed. vol. i. p. 129 (1848-52). 



2 Ann. Sci. Geol. vol. vii. pi. xxxiii. figs. 161-163. 



3 The exact position of the bed from which this fossil was obtained is given 

 in the memoir cited. In the Quart. Journ. Geol. Soc. vol. xrrvi. p. 383, Boyd 

 Dawkins mentions the occurrence of Hycenodon leptorhynchus in the Headon 

 beds. This statement probably rests on a misidentification of the present 

 specimen. 



