FOSSIL AXD EECENT LAGOMOEPHA. 439 



est d'ailleurs petit et qui, a un Age plus avance, eut etc confoadu avec le second lobe de 

 lameme dent, commecela se roit chez le sujet de la figure 2" {T. vlsenoviensis) ; and he 

 goes on stating, as Pomel had done for his Lagodus, that this little posterior column is 

 gradually worn away. It is mentioned by Gervais only in the last molar, and his iigures 

 show no trace of it in the anterior molars. 



Referring to Pomel's Lagodus and Amphilagus, Gervais launches an ungenerous and 

 unfounded accusation against this author, alleging that the former genus is " du moins 

 en partie " based on his, Gervais', figure of Titan, trilobus, and that An/pkilagus rests ou 

 fig. 2, representing Titan, visenoviensis. jSo mention is made of Pomel's description of 

 the upper dentition of " Lagodus.'' If the latter writer failed to recognize in his Lagodus 

 and AmiMlagtis H. v. Meyer's Titanomys visenoviensis, it was perfectly excusable at the 

 time he wrote, wlien this species had been so very imperfectly diagnosed both by 

 H. V. Meyer and by Gervais, who both failed to make out the 2)attern of the upper 

 teeth. Up to this day we have not been ])etter oflp with regard to the upper cheek-teeth 

 from the type-locality Weisenau. 



It would have been fairer on the part of Gervais to acknowledge that Pomel's 

 descrijition of the inferior molars of " Lagodus " had gone far in enabling him 

 (Gervais) to recognize the non-validity of his species T. trilobus, and that Pomel had 

 besides described more accurately than himself tlie lower teeth, in demonstrating the 

 presence of the " petit pli d'email " in all the posterior teeth of younger specimens. He 

 certainly could not have based this statement on Gervais' fig. 1 of the young specimen, 

 where only the last molar shows a posterior appendage. The accusation with regard 

 to Amphilagus is quite as unfounded as the first one. Pomel assigns five teeth to the 

 lower jaw' of his genus, Gervais' figure shows only four ; the description of the first tooth 

 of Amphilagus does not exactly agree Avith the tooth in Gervais' figure, from which last, 

 moreover, it could not be made out that the two cylinders of each of the posterior teeth 

 are united by cement, as stated by Pomel to be the case in his Amphilagus. Other 

 particulars occur in the description of Amphilagus, which miglit at once have convinced 

 an impartial critic that Pomel based his descrij^tion on originals. These were, many 

 years later (1879), handed by M. Pomel himself to Prof. Pilhol *. 



In his posthumous paper (1870) on the skeleton of a young Titanomys visenoviensis 

 from the Lignite of Ptott near Bonn, now in the British Museum (No. 41085), H. v. 

 Meyer mentions rooted cheek-teeth in Titanomys, and he has been understood to 

 state that only the deciduous teeth of this genus are provided with roots. However, 

 when reading attentively H. v. Meyer's paper — I might almost say, in reading between 

 the lines as well — one necessarily comes to the conclusion that in adult specimens 

 the permanent molars were also rooted, and that the author himself had suspected this 

 fact, but hesitated to jiroclaim it. Two kinds of rooted Titanomys-teeth are mentioned in 

 the paper. With regard to those of the Ilott skeleton, the author states that their 

 triturating surfaces are concealed in the matrix, so that their opposite ends only could be 

 examined ; but this does not hide the fact, he continues, that the two posterior upper 



* Aim. Sc. GJol. X. pp. 27, 28 {ISJ'J). 



