UNGULATA. 43 



MASTODON ARVERNENSIS, CROIZET JOBERT. 



By far the greater number of Mastodon teeth found in the 

 English Crags are referable to M. arvernensis. The species ac- 

 cording to Dr. Falconer (Pal. Mem., Vol. II., p. 28, 1868), is 

 characterised by the transverse ridges being each formed by two 

 pairs of thick high mammillae, with transverse valleys interrupted 

 by large accessory inammillse ; while the inner and outer portions 

 of the ridges alternate to a greater or less extent. 



Prof. Prestwich (Quart. Journ. Geol. Soc., Vol. XX VII, p. 118, 

 1871) includes this species among the Coralline Crag Vertebrates; 

 but in a note wives the following quotation from Prof. Lankester 

 (ibid., Vol. XXVI, p. 497) : " A Mastodon tooth which I have 

 seen from that situation [bed below the Coralline Crag] is not 

 M. arvernensis, but belongs to the Trilophodont species." 

 Mr. Gunn (Geol. Mag., Vol. VI., p. 237, 1869) has also noticed a 

 Mastodon tooth from the Coprolite bed below the Coralline Crag 

 at Button. One cannot, however, say to what species this 

 specimen belonged. 



Mastodon arvernensis is well known from the Norwich and 

 Red Crags of many localities in Norfolk and Suffolk. In France 

 it has been recorded from the Lower Pliocene at Montpellier, 

 and from the Upper Pliocene at Mont Perrier, &c. ; also from 

 Pliocene strata in the Val d'Arno, in Germany, and in Croatia. 



MASTODON LONGIKOSTEIS, KAUF 



To this species Mr. E. Lydekker (Quart. Journ. Geol. Soc., 

 Vol. XLII.j p. 365, 1886) has referred certain specimens from 

 the Red Crag of Suifolk, preserved in the British Museum, and 

 also the tooth from near Woodbridge, figured and described by Prof. 

 Lankester (Quart. Journ. Geol. Soc., Vol. XXVL, Plate xxxiv., 

 fig. 1, 1870) as nearly allied to, if not identical with M. Borsoni. 

 This tooth, which is now in the Reed Collection, York Museum, Mr. 

 Lydekker is convinced is a part of a tetralophodont tooth, and 

 cannot therefore belong to the trilophodont M. Borsoni; and 

 besides this, the portion preserved agrees with M. longirostris. 



The characters by which the teeth of the present species are 

 distinguished from those of M. arvernensis are pointed out by 

 Dr. Falconer (Pal. Mem., Vol, II., p. 29, 1868) and are thus shortly 

 given by Mr. R. Lydekker (Cat. Foss. Mamm. Brit. Mus., Part iv., 

 p. 62, 1886). " The columns of the cheek-teeth are separated by 

 a deep longitudinal cleft, but are arranged in the game trans- 

 verse line; the accessory tubercles are of moderate size, and 

 one column of each of the earlier ridges wears into a distinct 

 trefoil ; the valleys are but slightly blocked, and do not contain 

 any appreciable amount of cement." 



