LOPHIODOXTID^. 623 



external basal lobe in the third premolar, but none or a rudiment on the 

 fourth. No internal cingulum on the premolars. The superior true molars, 

 although worn, show a prominent anterior external basal lobe, and no com- 

 plete internal cingulum. The base of the crown of the first premolar is 

 naiTOW anteroposteriorly, and it has two roots as in S. tapirinus. It is in 

 close contact with the second premolar, and is separated from the base of 

 the canine by a space a little less than its own anteroposterior diameter, 

 and less than the diameter of the canine. The base of the crown of the 

 latter shows that it is not a large tooth, and has a wide lenticular section. 

 The base of the external incisor is rather large, and is compressed. 



Meastirements of superior teeth. 



M. 



Total leugtli of superior series 0720 



Tot.'il length of molar .series 0310 



Total length of premolar series 0250 



Diameters base of canine ^''°t«''"P°^'''''i°"^ ^"^^ 



( transverse 0040 



Length of base of Pm. i 0040 



Diameters Pm. iii 5 •''°'«^°P''«*«""^ 0"'0 



( transverse 0078 



Diameters Pm.iv^'^"»"»P°«t,*irior 0070 



< transverse 0U90 



Diameters M.,ii^'^"**™I"'^'''"°^ 0100 



< transverse 0125 



Some superior molars in better condition than those last described 

 exhibit the following characters: The intermediate tubercles are fused 

 with the internal, forming a continuous cross crest, but their apices are dis- 

 tinguishable. The external cusps are subconical and are well separated. 

 The anterior and posterior cingula are strong, the external is weaker, and 

 it is wanting from the posterior part of the internal base of the crown. 



A portion of a mandibular ramus, supporting six molars, presents the 

 following characters: The teeth are a little smaller than those of 8. tapirinus, 

 the reduction being especially visible in the premolars. The cones of the 

 crowns are more distinctly separated by notches than in that species, and 

 are quite distinctly conic. The anterior ledge of the true molars is distinct, 

 and there is a median posterior tubercle of the first two, which is repre- 

 sented by the wide crenate-edged heel of the third true molar. The ante- 

 rior-internal cusps of the last two molars are double or bilobed ; that of the 

 first is last. The anterior cones of the fourth premolar are subequal, and 



