last upper and lower molars. Chumashius balchi cannot, therefore, be regarded as occurring in the direct line of development leading upward to the Recent tarsier. In lower dental formula Chumashius exhibits a closer relationship to Omomys and Hemi4codon than to Anaptomorphus and Tetonius. The character of the lower posterior premolars in Uintanius suffice to remove this Bridger genus from any c...