s_ 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 Mexico today and since
it occurs in the vicinity of the San Josecito area the specimens under
discussion are referred to this species.

Cryptotis mexicana (Coues)

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 Mexico in contrast to _C. nelsoni_ which is restricted to Volcan de
Tuxtla, Veracruz. The northernmost Re