Comparison of the Pleistocene specimens with specimens of Recent species of North American _Sorex_ reveals that the presence or absence of the post-mandibular foramen is almost constant in any one species. In possessing this foramen the fossils differ from most individuals of the species: _Sorex cinereus_, _S. pacificus_, _S. milleri_, _S. vagrans_, _S. obscurus_, _S. ornatus_, _S. fumeus_, _S. palustris_, _S. bendirii_, and _S. veraepacis_. The fossils differ from all these species in other characters as well; consequently detailed comparisons with them need not be made here. Species which possess the post-mandibular foramen include _Sorex saussurei_, _S. merriami_, _S. trowbridgii_, _S. arcticus_, _S. tundrensis_, and _S. sclateri_. _Sorex merriami_ differs in smaller size, smaller and weaker dentition, relatively higher coronoid, and relatively deeper and shorter dentary. _Sorex trowbridgii_ is similar to the fossils and to _S. saussurei_. Differences between the jaws of _S. trowbridgii_ and _S. saussurei_ seem to me to be differences of size only. _Sorex sclateri_ is larger than the fossils and m2 is longer in relation to m1, being almost the same size as m1. In the fossils m2 is noticeably shorter than m1, owing to close appression of the hypoconid and protoconid and in general to a smaller talonid area. _Sorex arcticus_ differs in larger incisor and p4. _Sorex tundrensis_ differs in relatively narrower molars. 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 San Josecito collection contains 22 rami of a species of _Cryptotis_. Many are nearly complete although none possesses the incisor. In addition there is a rostrum that on the right side bears the last two unicuspids, P4, M1, and M2. I have compared these fossils with specimens of the following species of _Cryptotis_: _C. mexicana_, _C. magna_, _C. nelsoni_, _C. thomasi_, _C. alticola_, _C. parva_, _C. orophila_, _C. pergracilis_, _C. guerrerensis_, _C. obscura_, _C. mera_, _C. soricina_, _C. fossor_, _C. goodwini_, _C. griseoventris_, _C. meridensis_, _C. mayensis_, and _C. micrura_. 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 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. The rami of San Josecito specimens closely resemble those of _C. mexicana_ in both size and qualitative characters. The rostrum mentioned above differs from those of _C. mexicana_ in that the unicuspids are larger, especially the posteriormost one. _Cryptotis thomasi_ and _C. magna_ are eliminated from consideration here on geographical grounds. Little difference may be seen between the rami of _C. mexicana mexicana_ from Veracruz and _C. nelsoni_. The fossils are referred to the former species since it has a rather wide distribution in México in contrast to _C. nelsoni_ which is restricted to Volcán de Tuxtla, Veracruz. The northernmost Recent occurrence of _C. mexicana_ known to me is from Las Vigas, Veracruz. As far as I know the species has not previously been recorded from the Pleistocene.