cuina, Chihuahua.

_=Artibeus lituratus palmarum=_ Allen and Chapman.--This species has
been reported once previously from Sinaloa (from 1 mi. S El Dorado by
Anderson, 1960:3). Six specimens (85668-72, 85674), all males, collected
on December 23 and 24, 1960, at P['a]nuco, 22 km. NE Concordia, provide the
second known occurrence in the state.

_=Artibeus toltecus=_ (Saussure).--A male (85666) from P['a]nuco, 22 km. NE
Concordia, provides the first record of this species from Sinaloa and
extends the known range northwestward approximately 182 miles from Ambas
Aguas [= 6-1/2 km. SW Amatl['a]n de Jora], Nayarit (Andersen, 1908:300).
Our specimen was taken on December 22, 1960, in a mist net placed across
a road in an area where vegetation consisted mostly of weeds, grasses
and shrubs. Two _Glossophaga soricina leachii_ and two _Choeronycteris
mexicana_ were taken in the same net.

Davis' (1958:165-166) key is useful in separating the small Mexican
members of the genus _Artibeus_, but we have found some adults of
_toltecus_ to be smaller than the key indicates. For example, in the 12
Mexican specimens (Oaxaca, 6, Tamaulipas, 3, Jalisco, 2, Sinaloa, 1)
examined by us the total length of skull varies from 19.7 to 21.0 and
the forearm from 36.3 to 42.6.

Dalquest (1953) and more recently Koopman (1961) regarded _A. toltecus_
and the larger _A. aztecus_, which occurs in the same areas but at
higher elevations than _toltecus_, as subspecies of the more southerly
_A. cinereus_. Davis (_op. cit._), on the other hand, recognized
_toltecus_, _aztecus_, and _cinereus_ as distinct species. More
specimens of small and medium-sized _Artibeus_ are needed from M['e]xico
before this baffling complex can be studied adequately, but on the basis
of specimens examined we are inclined to agree with Davis as concerns
the specific distinctness of _toltecus_ and _aztecus_. In Tamaulipas
(the mammalian fauna of which is currently under study by Alvarez) for
example, _toltecus_ is known from Rancho Pano Ayuctle at an elevation of
300 feet in tropical deciduous forest, whereas _aztecus_ has been taken
only four miles away at Rancho del Cielo, but at an elevation of 3000
feet in cloud forest. The altitudinal difference between ranges of the
two kinds in Tamaulipas corresponds to that found in Sinaloa (see
Koopman, _loc. cit._) and is of approximately the same magnitude found
by Davis at higher elevations in Guerrero. This relationship suggests
tha