James S. Findley

“ I have compared the fossils also with the Pliocene and Pleistocene Sorex taylori Hibbard, and find that the fossils are larger and have larger teeth and a much wider separation of the protoconid and metaconid. I can find no significant way in which the fossils differ from S. saussurei. This of course implies similarity to S. trowbridgii. Since S. saussurei is a widespread species in México today and since it occurs in the vicinity of the San Josecito area the specimens under discussion are referred to this species. ”

“ The post-mandibular foramen is large and the opening of the mandibular canal is within the posterointernal ramal fossa. In addition the coronoid does not incline anteriorly. Specimen "A" is intermediate between No. 3943 and "B" in the characters mentioned and differs from both in that the post-mandibular foramen is widely separated from the mandibular foramen.
Comparison of the Pleistocene specimens with specimens of Recent species of North American Sorex reveals that the presence or [Pg 637] absence of the post-mandibular foramen is almost constant in any one species. ”

“ The four species first mentioned and the fossils seem to fall into one group. The remaining species fall into another group characterized by a smaller occlusal area of the talonid on all three molar teeth with respect to the trigonid, and [Pg 638] especially by the smaller and weaker talonid of m3 which possesses only one bladelike cusp, the hypoconid. In the first four species the talonids are larger than in the other species when compared to the trigonids, and the talonid of m3 possesses a well developed hypoconid and entoconid with a distinct basin between them. ”