LOPHIODONTID^. 621 



molar, and the base of the crown has a rovind section. The first premolar 

 has one root with a round section. There is variation in different individ- 

 uals as to its size relative to the canine, as it is sometimes larger and the 

 canine sometimes smaller. The crown is lenticular in section. It has a 

 posterior basal cingulum with a little apex. The remaining three premo- 

 lars have bases of about equal anteroposterior extent. The second has a 

 simple compressed and acute crown, while the two others have an internal 

 lateral tubercle. None have an anterior basal tubercle, but the third and 

 fourth have an anterior lobe below the apex. The heels of all three are 

 wide behind, and that of the second is short. The heels of the third and 

 fourth are longer, and have a submedian keel and no tubercles. No cingula 

 on the premolars. 



The transverse crests of the inferior true molars are slightly oblique, 

 and their extremities are a little more elevated than the middles, the internal 

 extremity the most so. They all have a well-marked transverse anterior 

 ledge, and the first and second have a posterior cingulum which is tliick- 

 ened at the middle. There is a trace of an external cingulum, but none of 

 an internal one. The heel of the third molar is very large and has an ele- 

 vated border. Enamel slightly wrinkled where not worn. 



The symphysis mandibuli is coossified, and there is a slight diastema 

 T^ehind the first premolar. The other teeth are in a continuous series. At 

 the tliastema there is a concavity in the side of the superior part of the 

 ramus, narrowing- the alveolar edgfe. There is a mental foramen below tlie 

 anterior edge of the second premolar, and another below the anterior edge 

 -of the canine, which looks downwards. The masseteric fossa is defined on 

 the side of the ramus by an obtuse angulation of the surface, and anteriorly 

 'by a rounded ridge. The infei'ior edge of the ramus is narrower. 



Measurements. 



M. 



Xeiigth of superior molar series ^ 0630 



Xength of premolar series 0300 



Length of base of Pm. i 0050 



-I-,. , ^-r, ...(transverse 0094 



JJiameters crown ot Fm. iu< 



( anteroposterior 0090 



-r^. . J? T> • (transverse 0110 



Diameters crown ot Pm. iv^ 



i anteroposterior 0090 



Diameters M.ii^=^"*^'"°I"'^»«"*'^ ^^^l 



i transverse Ol.iO 



