233 



ADDENDA. 



The two following specimens ivere presented after the 

 preceding pages were in type. 



Mastodon perimensis (page 56). 



M. 3499. The last three ridges and talon of a second (?) right lower 

 true molar, probably belonging to this species; from 

 Perim Island. Cement is present in the valleys. 



Presented bij Col. J. W. Watson, 1886. 



Mastodon cautleyi (page 71). 



M. 3500. The first three ridges (the third wanting the inner column) 

 of the germ of the second left upper true molar of a 

 small individual ; from Perim Island. This specimen, in 

 which the width anteriorly is 0,078, is rather smaller than 

 JSTo. M. 2887 (page 72), but agrees in every detail of struc- 

 ture. Presented by Col. J. W. Watson, 1886. 



PART IV. 



