of _goldmani_ and _artus_.

The morphological intermediacy of the specimens from four and a half
miles southeast of Alamos and of those from four miles north of
Terrero, along with the geographic intermediacy of the two localities
where the specimens were obtained constitute basis for arranging
_artus_ as a subspecies of _goldmani_ that has one page of priority.

[Illustration: MAP 1. Geographic distribution of _Perognathus
goldmani_. The black dots are known localities of occurrence.

1. _P. g. artus_

2. _P. g. goldmani_]

~Perognathus goldmani goldmani~ Osgood

_Perognathus goldmani_ Osgood, N. Amer. Fauna, 18:54,
September 20, 1900, type from Sinaloa, Sinaloa.

_Range._--See map 1.

_Measurements._--Average of five topotypes (Osgood, _op.
cit._:55): total length, 202; tail vertebrae, 112; hind
foot, 28; occipitonasal length, 27.7; mastoidal breadth,
14.5; greatest width of interparietal, 7.4.

_Records of occurrence_ (in each state the localities are
listed from north to south).--Sinaloa: 2-1/2 mi. N El
Fuerte, 25 K. U.; Sinaloa (Osgood, N. Amer. Fauna, 18:55,
September 20, 1900); 10 mi. NNW Los Mochis, 18 K. U. Sonora:
1 mi. E Buena Vista, on Rio Yaqui Reservoir, 1000 ft., 2 K.
U.; Camoa, 7 (U. S. N. M.); Tesia (Burt, Miscl. Publ. Mus.
Zool., Univ. Michigan, 39:46, February 15, 1938); Alamos, 7
(U. S. N. M.); 4-1/2 mi. SE Alamos, 1000 ft., 5 K. U.;
Chinobampo (Burt, _loc. cit._); 3 mi. NNW Bacarachi
[= Bacavachi], 2 K. U.

~Perognathus goldmani artus~ Osgood

_Perognathus artus_ Osgood, N. Amer. Fauna, 18:55, September
20, 1900, type from Batopilas, Chihuahua.

_Range._--See map 1.

_Measurements._--Average of five adult topotypes (Osgood,
_op. cit._:55, 63): total length, 191; tail vertebrae, 106;
hind foot, 24.6; occipitonasal length, 25.4; mastoidal
breadth, 12.4; greatest width of interparietal, 7.1.

_Remarks._--Considerable individual variation has been noted in each of
several populations of _Perognathus goldmani artus_. For example, in 14
adults from Culiacan, Sinaloa, the variation is 25.0 to 27.9 in
occipitonasal length and in mastoidal breadth is 12.6 to 14.0. Ten
specimens (83122-83131 Univ. Mich.) labeled as from Carimechi, Rio
Mayo, Chi[huahua], were recorded by Burt and Hooper (Occas. Papers Mus.
Zool., Univ. Michigan, 430:6, May 27, 1941) as from "near Carim