(iKp:c;()RY: nothahctus, an American eocene primate 199 



Thus the subfamily NotharctincC is distinguishod from the family Lemuridae by the following primi- 

 tive characters: lower incisors spatulate or truncate, not procumbent and styliform; lower 



CANINES CANINIFORM, NOT INCISIFORM OR STYLIFORM; pi PRESENT; Po SMALL AND PREMOLARIFORM, NOT 

 enlarged, COMPRESSED, TRENCHANT OR CANINIFORM. 



9 



Fig. 74. bower jaws of A'(>/7;r/r(7'(/.v and Lc pihiiinr . Lateral aspect. Natural size. 



1. Notharclas venticolm. Amer. Mus. No. 14655. Lower Eocene, Lost Cabin beds, Wind River basin, Wyoming. Natural size. 



2. Lepilemur nmstelinus. Amer. Mus. No. 31251. Natural size. 



Dissection of a lemur shows that all the lower and side teeth are pressed forward and outward by 

 the greatly enlarged tongue, which settles into the interstices between the teeth and fills the concavities 

 of their lingual surfaces. Especially the enlarged lower po is pressed forward against the rear of the upper 

 canine while the incisors and canines are pressed forward and extended beneath the tongue. The small 

 Pi of the ancestral lemuroids, which is nearly always a feeble tooth, has been crowded out of existence. 

 The sublingua seems to have little to do with this peculiar modification of the front teeth, since it lies 

 behind them above the dorsal slope of the symphysis. 



Lemurs are said to feed on fruits, buds, insects, eggs and small birds; the procumbent lower front 

 teeth may be used as scrapers as in M yoxicebus ^ ; doubtless the large upper canines and lower p2 are 

 used in puncturing fruits, eggs, and the skulls of young birds; the motion of the jaw is chiefly orthal, 

 with some ental movement. In correlation with the dwindling of the lower canines the mandible in 

 typical Lemurida) becomes shallow and relatively weak, with a flat lower border and reduced muscle 

 areas, the zygomatic arch and temporal crests also become weak, although the anterior part of the masseter 

 .below the orbit remains strong. 



In discussing the " Vordergebiss " (incisors and canines) of the Adapidae and other primates Dr. 

 Stehlin (1916, p. 1529) says: 



Eine sehr verbreitete, man kann sagen die lierrseliende, Aiisieht geht dahin, die caniniforuie Aiisliildung dcs Mandi- 

 bularcaninen, welche innerhalb der Primatenordming das Hauptcharacteristicum des 'Affentypus' ist, sei bei den Sauge- 

 tieren im allgemeinen ein schlechthin primitiver Znstand. So urtheilt, in der uns hier im speciellen beschaftigenden Frage, 

 ziim Beispiel Gregory, wenn er das Vordergebiss von Adapis im Vergleich zu dem von Lemur kurzweg als primitiv hinstellt. 



The writer is unable, however, to find any passage in his own writings containing anything at all 

 like the view which Dr. Stehlin erroneously attributes to him. The writer certainly never represented 



' Elliot, D. G., 1912, I, p. 129. 



