280 BR. A. S. WOODWARD ON SOME MAMMALIAN [May I9II, 



# 



molars opposed to them in the other jaw. The generic determina- 

 tion of isolated teeth is thus impossible, until a series of complete 

 jaws has been discovered ; but, as molars with a double row of 

 crescentic cusps have already been noticed by Marsh 1 as species 

 of ' Dipriodon,' it is perhaps convenient to use this appropriately- 

 descriptive name also for the new tooth now described. It repre- 

 sents a very much smaller species than either of those from the 

 Upper Cretaceous of Wyoming named by Marsh, while the cusps of 

 the dental crown are less regular in size and arrangement than in 

 the latter. For purposes of reference the tooth may, therefore, be 

 recorded under the name of Dipriodon valdensis. 



Discussion. 



Mr. C. Dawson thanked the Author for his kind encouragement 

 and readiness at all times to assist in the determination of his 

 specimens, and remarked that in the English Wealden there are 

 three horizons where bone-beds constantly occur, namely: — (1) In 

 the Upper Tunbridge Wells Sands, just below the Weald Clay 

 (being the true ' Tilgate Grit' of Mantell) ; (2) at a great depth 

 below the former, at the base of the Wadhurst Clay, in the blue 

 ■clay above, and sometimes associated with, the thick bed of cal- 

 careous sandstone (' Blue Stone ') ; and (3) about 26 feet below 

 No. 2 (at Hastings), at the top of the Ashdown Sand : it is less 

 fossiliferous than either of the former, and is usually associated 

 with bands of calcareous sandstone. So far, mammalian remains 

 had not been discovered in No. 1 : Nos. 2 & 3 had yielded the 

 teeth ascribed to Plagiaulax, and now No. 3 had also furnished 

 Dipriodon. 



During the last twenty years the speaker had disintegrated and 

 microscopically examined many tons of Beds 2 & 3 ; and during the 

 last two years he had been favoured with the patient and skilled 

 assistance of MM. P. Teilhard de Chardin and Felix Pelletier, to 

 whom the discovery of the multituberculate tooth (Dipriodon) was 

 due, as well as several new forms not mammalian. He was glad 

 to be able to say that, by the kindness of his colleagues, all these 

 specimens are to be ceded to the British Museum. 



Prof. W. Boyd Dawkins, after an allusion to his find, in years 

 gone by, of Hypsiprymnopsis rliceticus, expressed his pleasure that 

 the bone-beds of the Wealden were being worked at steadily : there 

 was a most wonderful development of these hone-beds in the 

 neighbourhood of Battle. He hardly thought that the affinities of 

 the mammalian teeth now described were with the Monotremes 

 (Prototheria), but rather with the Marsupials (Metatheria). It was 

 remarkable to find in the Eocene of both the European and the 

 American continents so specialized a type as Plagiaulax ranging 

 through from the Purbeck. 



Dr. Henry Woodward bore testimony to the valuable services 



i Op. cit. p. 85 & pi. ii, figs. 13-18. 



