MACACUS. 



Another specimen of a fossil tooth of the Macacus eoctenus 

 had been previously discovered, 1888, in the same stratum 

 and locality as the fossil above described. It was sub- 

 mitted to my inspection by Mr. Lyell, who has commu- 

 nicated the result of my comparisons in the " Annals of 

 Natural History," for November 1839, proving it, likewise, 

 to be the molar of a Monkey of the genus Macacus, thus 

 constituting at once the first terrestrial mammal which 

 had been found in the London Clay, and the first Quadru- 

 manous animal hitherto discovered in any country in tertiary 

 strata so old as the Eocene period. 



The specimen in question consists of the crown and 

 one fang of the first true molar tooth, and is marked 

 m, 1, in the cuts figs. 1 and 3. The series of teeth in the 

 recent lower jaw, figs. 2 and 4, figured for comparison, is 

 divided into two incisors, marked ', one laniary, or canine, 

 marked , two premolars, or false molars, (called bicuspides 

 in human anatomy,) ^>, and three molars or true molars, 

 of which the analogues of the fossil teeth are marked re- 

 spectively m, 1, and m, 3. The crown of the false molar 

 of the fossil Macacus, (m, 1, figs. 1 and 3,) presented four 

 tubercles, arranged in two transverse pairs, the anterior pair 

 being the highest ; there was, also, a very small ridge 

 across the anterior, and another across the posterior part 

 of the crown. The latter is placed between, and connects 

 together the two posterior tubercles. The fangs were 

 two in number, strong, and divergent : the tooth had be- 

 longed to an animal that had passed its maturity, the tu- 

 bercles having been worn at their summits, and the posterior 

 concavity having been smoothly deepened by attrition. 



It differed from the corresponding tooth in the existing 

 Macacques, in having the ridge along the base of the 

 forepart of the crown, and by being relatively narrower 



