560 bulletin: museum of comparative zoology. 



joints of funiculi, a large spot on the prono.tum, a smaller one on the 

 mesonotum, the upper surface of the petiole, the coxae, femora and 

 in some specimens also the apical half of each tibia and the pleurae, 

 dark brown or fuscous. 



Type locality. — Arizona: Bright Angel Trail, Grand Canyon 

 5,500-7,000 ft. (Wheeler). 



Arizona: Prescott (Wheeler). 



Utah: Milford (J. C. Bradley). 



This species appears to belong in the yallidcfuha group, although 

 the sculpture of the body is very unlike that of the preceding species. 

 Superficially it resembles F. rufibarbis, but the head, thorax, and an- 

 tennae are much more like those of yaUidcfulm. There is, however, 

 much that recalls Myrmecocystus in the structure of the thorax seen 

 in profile. 



F. mold nests under stones and forms colonies about the size of those 

 of F. pallidcfulva and its various subspecies and varieties. It probably 

 represents this species in the dry deserts of the southwest, but is 

 certainly a much rarer ant. 



Addendum. 



The following notes and descriptions relate to specimens discovered 

 after the manuscript of this paper was ready for the press. 



140. F. truncicola integroides var. ravida, var. nov. 



Worker. Length 4-6 mm. 



Like the var. haemorrhoidalis Emery in pubescence and sculpture 

 and in lacking erect hairs, except on the gaster, but differing in color. 

 The red of the head, thorax, and petiole is much deeper and not 

 yellowish, the legs, whole of the funiculi, tips of the scapes and the 

 gaster are black and even the largest workers have a large black spot 

 on the pro- and mesonotum. In small workers the red color is darker 

 and more brownish, the whole thorax is blackish and the posterior 

 portion of the head and the whole of the scapes are infu seated. The 

 surface of the body in all of the workers is opaque, the pubescence 

 on the gaster short, dense and dark gray in color; the red anal spot 

 is much restricted. 



Female. Length 8.5-9 mm. 



Differing from the female of haemorrhoidalis in having the tips of 

 the scapes, the posterior border of the pronotum, three spots on the 



