igo6.] Wheeler, The Ants of the Grand Caiion 343 



the Indian Garden. There I also found a sohtary dealated female, with 

 a cluster of small larvae in the act of establishing her formicary. Many 

 of the workers in these colonies were in a replete condition, indicating 

 that they got their food from aphids or coccids. In the northern 

 States I have seen hundreds of nests of this ant but on only two occa- 

 sions have I found it nesting under stones. In fact, it seems to have 

 as great an aversion as Dorymyrmex pyramiciis to nesting in such 

 places. In the Grand Canon it is probably compelled to abandon its 

 usual habits and to nest under stones for protection against the 

 scouring rains. 



2 2 . Lasius niger Linn. var. amerlcanus Emery. — A small yellowish 

 form of this variety is common under stones in the Kohonino Forest 

 on the rim of the canon and occurs also but more sparingly at the 

 Indian Garden. It is also common on the rocky hills about Prescott, 

 Arizona, and Las Vegas, New Mexico, where the soil and elevation 

 are like those on the rim of the canon. 



23. Formica moki sp. no v. 



Worker. Length 4-5.5 mm. 



Mandibles 8-toothed. Palpi long and slender. Head decidedly longer than 

 broad, with rather straight sides, converging anteriorly, posterior margin 

 straight, posterior corners rounded. Eyes large and convex. Clypeus with a 

 very prominent keel, its anterior border entire, projecting in the middle. An- 

 tennae slender, three basal funicular joints more elongated than joints 6 to 8 ; 

 first and third joints equal, longer than the second joint; none of the joints 

 less than twice as long as broad. Thorax long and narrow, in profile ver\^ low ; 

 pro- and mesonotum depressed, mesoepinotal constriction shallow and very long 

 at the bottom. Epinotum with flat basal surface, nearly twice as long as the 

 very sloping declivity. Seen from above the pronotum is as long as broad > 

 mesonotum nearly twice as long as broad. Petiole narrow, thick at the base* 

 with sharp, horizontal upper border, and both the anterior and posterior sur- 

 faces, but especially the latter, distinctly flattened, so that the segment is cuneate 

 in profile. Gaster small. Legs long and slender. 



Subopaque; frontal area, sides of clypeus and bases of mandibles somewhat 

 shining. Blades of mandibles rather coarsely striatopunctate. Head behind 

 with a bronzy or glossy surface. 



Body and appendages covered with fine grayish pubescence, which is densest 

 and most conspicuous on the gaster and posterior portion of the head, sparser, 

 but still readily discernible on the upper surface of the thorax and petiole and 

 lower surface of the head. On the gaster a few of the hairs along the posterior 

 borders of the segments are thick and obtuse. Legs with graduated, oblique, 

 tapering hairs on the flexor surface of the tibiae. 



Dull reddish yellow; gaster dark brown or fuscous, as are also the posterior 

 half of the head above, a large cloud on the pronotum, another on the mesono- 

 tum, the upper portion of the petiole, the coxae, femora, and in some specimens 



