44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



and its lower extremity forms a high median crest on a usually broad 

 and well-developed talonid. 



P 4 is quite molariform and differs from the anterior molars essen- 

 tially in the relatively longer and somewhat narrower trigonid portion 

 with its more widely open crescent. This anterior crescent may also 

 show somewhat better evidence of a distinct paraconid than in the 

 molars. Also, the posterointernal extremity of the posterior crescent 

 may be more medial and often shows an extra cusp. 



The first two molars, as in the upper series, are much alike with 

 M 2 noticeably larger. They are highly selenodont with the posterior 

 or talonid crescent a little more elongate anteroposteriorly than the 

 anterior or trigonid crescent, and the outer walls of the crescents are 

 more hypsodont than the inner walls. The anterior crest of the 

 trigonid is somewhat recurved posteriorward at its lingual extremity 

 but is not raised to form a definable paraconid. The metaconid 

 and entoconid (or hypoconulid?), however, are well denned and 

 relatively high in unworn teeth. The anterior crest or crista obliqua 

 of the hypocone joins the anterior crescent at the metaconid a little 

 below its apex, and on the posterior slope of this cusp there is almost 

 invariably a well-developed and somewhat lingually flexed meta- 

 stylid crest which may show a distinct cuspule. This tends to con- 

 strict the talonid basin lingually and there may also be a small extra 

 cuspule at the mouth of the valley or basin. 



M 3 differs from the anterior molars only in that the talonid portion 

 is a little more elongate and slightly narrower. Moreover, there is a 

 buttresslike extension or crest on the posterior wall of the entoconid 

 (or hypoconulid?). The greater length and narrower talonid portion 

 is a development just the reverse of that observed in P 4 . 



Deciduous upper premolars. — Dp 8 is a rather distinctive tooth in 

 the upper series, and while it seems to show somewhat the same detail 

 as P 3 , it is very much askew with the talonid portion deflected 

 decidedly posterolingually rather than having the nearly symmetrical 

 appearance of the permanent tooth. Moreover the small cuspules 

 anteroexternal and posteroexternal to the deuterocone are very weak 

 or missing, whereas the outer wall shows a rather prominent develop- 

 ment of a style at the anterior extremity and the tritocone is better 

 denned than in P 3 . 



Dp 4 is almost indistinguishable from M 1 except for its smaller size 

 and greater wear, when found associated with it. It does, however, 

 show a relatively more forward position for the parastyle, and occa- 

 sionally the tooth is a little more askew than M 1 . It is, of course, 



