FORT UNION OF CRAZY MOUNTAIN FIELD, MONT. 165 



of Europe. The European Cheiromyoides Stehlin is a contemporary 

 and close relative of Plesiadapis. 



Nothodedes Matthew is clearly a synonym of Plesiadapis, as pointed 

 out by Teilhard and accepted by all subsequent students." Jepsen 

 (1930 and 1934) tentatively placed Plesiolestes in this group, but the 

 belief that it does not belong here has already been expressed above. 

 He also (1934, p. 290) rejects my redefinition (Simpson, 1929c) of 

 Plaiychoerops and its separation from Plesiadapis, but I have already 

 defended this at some length (1935c). 



Cheiromyoides Stehlin, accepted as valid by Abel, Jepsen, and 

 others but rejected as a synonym of Plesiadapis by Teilhard, differs 

 less from typical Plesiadapis than does typical Plaiychoerops . It evi- 

 dently represents an only slightly divergent and, as far as known, 

 sterile side branch of the phylum. 



Genus PRONOTHODECTES Gidley 



Pronothodectes Gidley, 1923, p. 12. 



Type. — P. matthewi Gidley. 



Distribution. — Middle Paleocene, Fort Union, Montana. 



Diagnosis.— Denta] formula 2ori.L3.3" Lower incisor much en- 

 larged, semiprocumbent, root laterally compressed. Canine (or 

 possibly Pi) small, slightly procumbent. P2 1-rooted. P4 with 

 quadrate base, short, high trigonid portion, no paraconid or meta- 

 conid. Talonid large with a single cuspule. Paraconid distinct on 

 all molars, anteroexternal to the metaconid and progressively nearer 

 the latter from Mi to M3. No metast5did, but a vague cusp on the 

 hypoconid-trigonid crest. M3 with third lobe and elevated postero- 

 internal rim with two or more pooz'ly differentiated apices. P* with 

 separate subequal paracone and metacone apices, their bases con- 

 fluent, large conule mass, and strong protocone, which is, however, 

 less expanded than in Plesiadapis. Upper molars Plesiadapis-\ike 

 but simple, without major cremdations or secondary cuspules, and 

 probably lacking the mesostyle (although this may be removed by 

 wear in the known material). 



PRONOTHODECTES MATTHEWI Gidley 



Plate 8, Figure 1; Plate 9, Figures 2, 11, 12; Plate 10, Figures 3, 3a 



Pronothodectes matthewi Gidley, 1923, p. 12. 



Type.— U.S.N.M. no. 9547, part of right maxilla wdth P^-M^. 

 Collected by A. C. Silberling. 



Parafypes.- — U.S.N.M. no. 9332, left lower jaw with incisor root 

 and crown of ?C, P2, P4, and M1-3. Collected by Dr. J. W. Gidley. 



8' It is, however, certain that Nothodectes gidleyi Matthew is specifically distinct from the European 

 Plesiadapis triscuspidens Gervais. 



