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BULLETIN 169, UNITED STATES NATIONAL MUSEUM 



patratus, but it is closer to the latter than to E. cuspidata and shows the 

 Elpidophorus line to have been distinct at this time. 



Dimensions of the type are as follows: Length P3, 2.0; width P3, 1.4; 

 length P4, 2.7; width P4, 1.9; length Mi, 2.8; width Mi, 2.6; length 

 M2, 3.0; width M2, 2.8. 



Figure 27 .—Elpidophorus minor, new specie?, Princeton Univ. no. 14201, left lower jaw: a, Crown view; &, 

 internal view. Six times natural size. 



7INSECTIV0RA, incertae sedis 



PICRODONTIDAE, new family 



Type. — Pier odus 'Douglass, 1908. 



Distribution. — Middle and Upper Paleocene, North America. 



Diagnosis. — -Minute insectivoreUke or batlike forms of doubtful 

 ordinal affinities, with one pair of greatly enlarged incisors (at least 

 in lower jaw), muzzle long and slender, canines reduced, premolars 

 small with no tendency to molarization, molars large, brachyodont, 

 with shallow, expanded basms and indistinct cusp structure, adaptively 

 resembling molars of the recent Phyllostomatidae. 



Discussion. — At present only two genera, Picrodus and Zanycteris, 

 are referred to this family, and these are not directly comparable with 

 each other. The evidence for their close relationship is, however, 

 impelling, as discussed below. The separation of family characters- 

 from those merely generic is not entirely practicable in this stage of 

 knowledge, but there can be Httle doubt that these two genera do 

 belong to a family otherw^ise unknown, and the characters given in 

 the above diagnosis distinguish them from any other family. The 



