1987] 
Shattuck — Pogonomyrmex occidentalis complex 173 
random geographic distribution. This differs from closely related 
species in which dines are seen in many of these characters. Since 
there is a broad region of overlap (western Utah, Nevada, eastern 
California) of P. occidentalis and several other species, interbreed- 
ing would be expected to produce clinal patterns in both species 
involved. This was not observed in regions where P. occidentalis 
and related species are sympatric. 
P. salinus Olsen 
P. salinus Olsen, 1934: 510 (W). Type Loc.: near Soda Springs, Bridgeport, Mono 
Co., California, USA. 
P. occidentalis owyheei Cole, 1938: 240 (W, F). Type Loc.: Indian Cove, near Ham- 
mett, Elmore Co., Idaho, USA. (New Synonymy) 
Cole (1968) considered P. owyheei and P. salinus as distinct spe- 
cies and gave little discussion to the matter. The present study shows 
that many characters have clinal patterns not in support of Cole’s 
view. The gaster shows a clinal pattern with smooth states (1 and 2) 
in the north and smooth and rough states (3, 4 and 5) in the south. 
This partly supports the distinctness of P. salinus by limiting it to 
the southern portions of the range, but does not support the notion 
that P. owyheei occurs only in the north. PpDor shows a similar 
clinal pattern, with greater variation in the southern portions of the 
range and less variation in the north. PetDor differs from both of 
these characters in that it shows P. salinus- like states as occurring 
north into central Oregon, while P. owyheei- like states do not occur 
south of northern Nevada. The scape also incorrectly indicates the 
distributions of these two forms. As determined by the shape of the 
scape, P. salinus would extend northward into central Oregon, 
while P. owyheei would extend southward into east-central Califor- 
nia and southern Utah. 
Many specimens determined by Cole (primarily in LACM) sug- 
gest that color and distribution played a role in his actual determi- 
nations: dark specimens from southern areas were identified as P. 
salinus while light-colored individuals from northern areas were 
identified as P. owyheei . Since color is somewhat subjective and 
difficult to quantify I made no attempt to do so but did record it 
while making determinations. Cole (1968) mentioned color in his 
treatment of these species but did not use it as a distinctive character 
in his keys or discussion. 
