only concrete evidence of geographic variation that I
can detect in these animals is a slight increase southwardly in the
frequency and degree of melanism, a kind of variation that is unworthy
of taxonomic recognition in this species. It seems best, then, to
regard the name _Sciurus aureogaster hypopyrrhus_ Wagler as a synonym
of _Sciurus aureogaster aureogaster_ F. Cuvier.

Nelson (_op. cit._:45) stated that _S. a. frumentor_ "Differs
strikingly from typical _aureogaster_ in having well-marked nuchal and
rump patches of yellowish brown or rufous brown; the underparts gray
or gray washed with rufous; tail heavier and more bushy; pelage
softer.... Skull indistinguishable from that of typical
_aureogaster_." I have examined 22 specimens from Jico, 7 from Las
Vigas (the type locality), and one from 3 km. E Las Vigas, all in
Veracruz. These include the type and paratypes of _S. a. frumentor_.
Part (probably 7 specimens) of the series from Jico was referred by
Nelson (_op. cit._:46) to _S. a. frumentor_ and he thought, or knew,
these specimens to have been taken _above_ Jico. The remaining
specimens labelled as from Jico were referred to _S. a. aureogaster_.
I am unable to find fault with the characterization of _S. a.
frumentor_ insofar as color or skull are concerned. I cannot verify to
my own satisfaction the presence of "heavier" and bushier tail and
softer pelage. The characters considered to be diagnostic of _S. a.
frumentor_ are distributed in an interesting geographic pattern the
genetic import of which is not wholly clear. One specimen (No. 23945
KU) of the two available from 3 km. SW San Marcos, Veracruz, a
locality on the coast approximately 50 miles north of Las Vigas, is
indistinguishable from topotypes of _S. a. frumentor_ except for
slightly lighter-colored grizzled parts. The second specimen (No.
23946 KU) from the same locality, although a subadult in worn pelage,
shows the color and striking dorsal pattern of _S. a. frumentor_ and
the ventral color of _S. a. aureogaster_. The dorsal pattern of _S. a.
frumentor_ is found also in the three specimens from San Carlos and
Plan del Rio, Veracruz (Nos. 11082, 11083 and 8278), Chicago Nat.
Hist. Mus., respectively. (The two specimens from San Carlos were
referred to _S. a. frumentor_ by Elliot, Field Columb. Mus., Zool.
Ser., vol. 8, Publ. no. 115:128, February 9, 1907.) Nevertheless,
although the essential morphological characters of _S. a. frumentor_
occur spor