24 PACHYDERMATA. 



Whilst this discussion was taking place in America, the dis- 

 covery was made of a similar structure in a European species of 

 Mastodon, by Dr. Kaup. This distinguished palaeontologist first 

 proved the existence of two deflected and recurved tusks of large 

 size, in the lower jaw of his colossal genus Dinotherium, the teeth 

 of which had been referred by Cuvier to a gigantic kind of Tapir. 

 Soon afterwards, at Eppelsheim, in the same arenaceous deposit 

 which had yielded the Dinotherian remains, he discovered an adult 

 lower jaw of a species of Mastodon, which presented a remarkable 

 semi-cylindrical and beak-shaped elongation of the symphisis, form- 

 ing the sheaths of two inferior tusks, while the molar teeth exhi- 

 bited the characters attributed by Cuvier to a portion of the 

 specimens included by him under the names of M. angustidens. 

 Kaup, after recognising the structure, at first adopted Godman's 

 genus for the reception of his species, which he named T. longi- 

 rostris , J but, subsequently, in his great work upon the Eppelsheim 

 fossils, 2 he admitted the force of the objections raised by the 

 American naturalists against the generic importance of the inferior 

 tusks in Tetracaulodon, and referred the Eppelsheim fossil to the 

 genus Mastodon, retaining the same specific name. He extended 

 the observations made by von Meyer on M. Arvernensis, which 

 he considered to be the young of M. longirostris. He traced the 

 dental succession from the earliest to the adult stage, confirming 

 the observations made by Hays on M. Ohioticus, by showing that 

 six molars are developed in the European species during life, in 

 antero-posterior succession. Kaup also detected the presence of 

 an upper premolar, situated as a germ, above the second deci- 

 duous grinder, in a young specimen of M. longirostris, corrobo- 

 rating the inference drawn by Cuvier from the Dax specimen of M. 

 angustidens ; but he considered this tooth as the normal successor 

 of the first milk molar, the second of the series being the tooth 

 which it specially replaces. Dr. Kaup, in the first instance, took 

 a peculiar view of the affinities and systematic relations of his 

 most remarkable genus Dinotherium ; but he has since come 



' Isis, 1832, p. 623. 



' Ossemens Fossiles de Darmstadt, 1835, Part iv. p. 65-89. 



