Magazine of Zoology, Botany, and Geology. 243 



drumanous, Marsupial, and other Mammalia in the London 

 clay, near Woodbridge, in Suffolk, by Charles Lyell, Esq. 

 F.R.S., V. P.G.S. Mr. Colchester found in a bed of sand near 

 Woodbridge, which he supposed to belong to the London 

 clay formation, a tooth which he conceived to be that of a 

 mammiferous quadruped. Mr. Lyell requested Mr. C. to 

 conduct him to the spot, where Mr. L. found the deposit to 

 consist of brown clay laid open to a depth of 12 feet, and 

 below this sand in layers, yellow and white, which had been 

 pierced to a depth of 12 feet without reaching the bottom. 

 Precisely at the junction of the clay and sand, Mr. L. found 

 numerous teeth of sharks, similar to those which had been 

 found with the mammalian tooth. Mr. Lyell considers the 

 bed in which these remains were found as belonging to the 

 Eocene period, as they underlie the crag, and contain 

 septaria, shells, fruits, and bones of turtles, such as cha- 

 racterise the London clay. The tooth on being shewn 

 to Mr. Owen, was pronounced to be a molar of an opos- 

 sum, about the size of Didelphys virginiana. When sub- 

 sequently Mr. Owen instituted a more minute and exten- 

 sive comparison, with a view of giving an anatomical de- 

 scription of the tooth above mentioned, he discovered 

 clearly that it was not a Didelphys, but the molar of a 

 monkey of the genus Macacus, constituting at once the 

 first terrestrial mammifer which had been found in the 

 London clay, and the first quadrumanous animal hitherto 

 discovered in any country in tertiary strata as old as the 

 Eocene period. Soon after this Mr. Searles Wood visited 

 the spot where the tooth was found, and prevailed on Mr. 

 Colchester to search in the sand that had been previously 

 thrown aside from the bed containing numerous teeth 

 of sharks ; the result of his examination was the discovery of 

 a lower jaw, referred by Mr. Owen to the genus Macacus. 

 Pursuing his researches, Mr. Colchester afterwards met with 

 another jaw which Mr. Charlesworth has since described as 

 the jaw of an opossum, a genus to which it will be seen Mr. 



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