1908.] 



DR. FORSYTH MAJOR ON FOREST-BED MAMMALS. 



633 



Of the Swedish Beaver Matschie says that in the last upper 

 molar the internal enamel- fold is absent, " und bei den iibrigen 

 Molaren legt sie sich nicht an die vorderste Aussenfalte an, 

 sondern verlauft senkrecht zum Langsdiu'chmesser der Zahne 

 und endigt frei zwischen der vorderen und mittleren Aussenfalte." 

 Besides, " the nasals are obliquely truncated towards the front and 

 not notched near the intermaxillary, so that their anterior margin, 

 seen from the side, seems to be angularly notched." * 



Text-fia-. 135. 



A. 



B. 



Castor Jiher L. Sweden. Lower view of right upper molar series. Copied from 

 Meves's Atlas ofver Skaiidinaviens Daggdjur, Suppl. pi. iii. fig. la. 



Castor fiber L. Lapland. Lower view of right upper molar series of an old 

 specimen. R. Coll. of Surgeons Museum. 



Text-fig. 136. 



A. 



A. Castor fiber li. Peat-deposit, England. Lower view of right upper true molars. 



B. Castor fiber L. Lower Rhone (B.M. No. 94.5.30.1). Lower view of right 



upper molar series. 



An inspection of the figure to which Matschie alludes (see text- 

 fig. 135 A, which is a copy of the figure in Meves's Atlas) shows 

 that the internal enamel-fold is not absent from the last upper 

 molar, only it is fused with the antero-extei'nal fold, a condition 



* Op. cit. p. 216. 



