A NEW SPECIES OF ANT BELONGING TO THE 
PHEIDOLE PILIFERA COMPLEX 
(HYMENOPTERA: FORM1CIDAE) 
By Robert E. Gregg 
Department of Biology, University of Colorado 
A small collection of ants representing the genus Pheidole 
from several localities in Western United States was given 
to me recently by Dr. W. S. Creighton. Among these 
specimens are samples of several colonies from Oregon 
which prove to be a new species. The description of this 
ant follows herewith. 
Pheidole creightoni sp. nov. 
Soldier : Length, 3.75 mm.; head index, 0.94; head length, 
1.33 mm. ; thorax length, 1.00 mm. 
Head subquadrate, slightly longer than broad, with prom- 
inent occipital corners and a deep occipital emargination 
leading to a pronounced cephalic sulcus. In profile, the 
occipital border is flat and slopes forward, but joins the 
vertex in a rounded though noticeable angle rather than 
through a continuous curve. Anterior clypeal border 
broadly emarginate in the center, the lateral borders nearly 
straight. Frontal carinae flat and slightly divergent. 
Frontal area well-defined and in the shape of an isosceles 
triangle. Eyes lateral and placed distinctly anterior to 
the middle of the head. Antennae 12-segmented, with a 
club composed of the last three articles; funicular segments 
5 to 8, slightly longer than broad ; antennal scape distinctly 
bent at the base, with only a faint indication of flattening, 
and with its distal portion definitely wider than the basal 
portion. The scape extends posteriorly a little less than 
one-half the distance from its insertion to the occipital 
corner of the head. Mandibles heavy, abruptly convex, 
and provided with two very blunt teeth at the apex; 
remainder of the cutting border entire. 
Thorax convex, with well-marked humeral angles; 
promesonotum does not descend before reaching the 
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