764 



Bulletin American Museum of Natural History. [Vol. XXIII, 



R of the table on p. 756, is greater owing to the elongation of the galleries 

 of the latter species. 



Like the species of Trachipnyrmex, M. harimanni leaves the rootlets 

 dangling into the chambers as suspensoria for its fungus-gardens (Fig. 28). 

 These gardens, however, have a much more delicate and flocculcnt texture 

 and are made up almost exclusively of the anthers of plants, knit together 

 by a snow-white mycelium consisting of slender hyphje .58 ii in diameter. 

 The bromatia, which measure .3-.4 mm. consist of typical pyriform gongy- 

 lidia 1.5-4.3 p. in length and 1.3-4 p. in breadth. 



The colonies are small, not exceeding 60 to 70 workers. Only a single 

 dealated female was found in each of the nests. I was unable to find any 



Fig. 29. Fungus garden ul Attn ^ M iirUx-'^i ili-: , tntrtmanni, removed from the nest intact 

 and placed on the ground. (.Photograph by Mr. C. G. Hartmann.) 



larvfe or pupa?. Mr. A. i\I. Ferguson, Avho helped me excavate a number of 

 the nests on one occasion, and kept the ants with some of their gardens in an 

 artificial nest, succeeded later in the summer in rearing the males and winged 

 females described on pp. 715-716. The workers are extremely timid and 

 "feign death" with the utmost readiness. Their small rough bodies are 

 then quite indistinguishable from the sand grains among which they lie. 

 Only a few workers forage or excavate at a time. They seek the withered 

 anthers where they have fallen or have been drifted by the wind on the sur- 

 face of the sand and slowly and laboriously transport them to their nests. 

 These anthers, many of which still contain pollen grains, are inserted entire 

 in the gardens and are evidently responsible for the light and flocculent 



