AMMOCH/ET/E. 1 89 



etc., brought into the nest. I had previously found that this 

 species does not feed its larvae by regurgitation but with pieces 

 of seeds or insects. 



Continuing my observation of the living harvesters I was soon 

 led to what I believe to be the true function of the macrochaetae. 

 Each of the fore legs, as in other Formicidae, bears a well-devel- 

 oped strigil, or enlarged and pectinated spur (Fig. 2) which in 

 the living insect is usually carried at an angle of about yo° with 



Fig. 2. Pogonomyrmex barbatus, fore tarsus, mesial side. 



the long axis of the tibia. The tibia is furnished at its tip on the 

 mesial side with a dense brush of blunt hairs and the metatarsus 

 is curved outward at the base, with a regular comb of fine bristles 

 at the concavity and a series of coarser and blunter bristles along 

 its whole mesial border. The pectinated strigil may be opposed 

 to the pectinated and concave base of the metatarsus, and is 

 especially adapted for cleaning the antennae, which are drawn 

 through the orifice between the two combs. 



McCook 1 has described and figured (PI. XIV., Fig. 64) the 

 fore leg of P. molefaciens. I quote the following from his detailed 

 account of the toilet habits (pp. 127-129) : "The ants engaged 

 in cleaning their own bodies have various modes of operating. 

 The fore legs are drawn between the mandibles, and, so far as 

 could be ascertained, also through or along the lips, and then 

 are passed alternately back of the head, over and down the fore- 

 head and face, by a motion which closely resembles that of a cat 

 when cleansing with its paw the corresponding part of her head. 

 Sometimes but one side of the head is cleansed, in which case 

 the foot used is drawn through the mandibles or across the teeth 

 of one mandible after every two or three strokes upon the face. 



1 "The Natural History of the Agricultural Ant of Texas, a Monograph of the 

 Habits, Architecture and Structure of Pogonomyrmex barbatus. " Author's edition. 

 Acad. Nat. Set. Pkila., 1879. 



