110 
Psyche 
[September 
The obtusopilosa complex, perhaps wrongly named at 
the outset because obtusopilosa is the least typical and 
most poorly known of the species, offers the following 
characters : 
(1) The worker coloration shows much interspecific 
variation, ranging from concolorous yellowish red to con- 
colorous black or red and black. 
(2) The workers average smaller in size than in the 
sanguinea complex, are more slender in body form, and 
have a poorly defined metanotum. 
(3) The propodeum is proportionately longer and more 
rounded, with little or no angle between dorsum and 
declivity. 
(4) The gastric pubescence is very sparse (except in 
obtusopilosa) and the body pilosity generally abundant. 
Hairs are usually present, and often abundant, on the 
dorsal face of the propodeum anterior to the propodeal 
angle. 
(5) The sculpture is usually feeble and the integument 
therefore more shining. 
(6) The male has relatively slender parameres and a 
subgenital plate of a distinctive conformation (figs. 4, 6). 
Explanation of Plate 11 
Fig. 1. Head of F. subintegra woiker from University of Michigan 
Biological Station, Douglas Lake, Cheboygan Co., Mich. (P. B. Kan- 
nowski). Head width 1.71 mm. Fig. 2. Head of putative F. curiosa 
worker from Culbertson, Roosevelt Co., Mont. (E. 0. Wilson). Head 
width the same as in subintegra ; specimen of fig. 1. Fig. 3. Left paramere 
of F. subnuda male from Woodland Park, Teller Co., Colo. (W. M. 
Wheeler). Fig. 4. Left paramere of F. perpilosa male from Ft. Davis, 
Texas (W. M. Wheeler). Fig. 5. Posterior border of subgenital plate 
of same specimen as in fig. 3 (F. subnuda). Fig. 6. Posterior border of 
subgenital plate of same specimen as in fig. 4 ( F . perpilosa). Fig. 7. 
Left side view of petiole of F. subintegra worker from Rogers City, 
Presque Isle Co., Mich. (P. B. Kannowski). Head width 1.63 mm. Fig. 
8. Left side view of petiole of F. subnuda worker from Kiowa, Glacier 
Co., Mont. (E. 0. Wilson). Head width 1.76 mm. 
