768 Bulletin American Museum oj Natural History. [Vol. XXIII, 



tion before they are inserted in the garden. The mycehum which binds 

 these sHvers together bears distinct bromatia .6-.7 mm. in diameter and 

 consisting of pear-shaped gongyhdia 1 .5-3.5 /« in length and .78-1.56 /i broad. 

 They are less globose than the gongylidia of Atta and Tmchymyrmex and 

 less club-shaped than those of the South American species of Cyphomyrmex 

 represented in jNIoeller's figures. Sometimes as in these species, however, 

 they are not terminal but appear as mere swellings in the course of the hyphse. 

 The brood is embedded in the fungus gardens and the eggs and young larvae 

 and often also the older larvje and pupae are covered with a delicate film of 

 mycelium. 



The ants carry all the exhausted particles of the substratum out of the 

 galleries and build them into a flat mass which adheres to the lower surface 

 of the stone. INIore rarely this refuse is dumped outside the entrance of the 

 nest at the edge of the stone. x\s the mass of slivers is sometimes nearly 

 as large as a man's hand and therefore greatly exceeds the size of the flour- 

 ishing gardens, one is compelled to conclude that the vegetable particles 

 contain but little available nutriment for the fungus and have to be con- 

 tinually renewed by the workers. Moreover, as these masses of exhausted 

 substratum are often found under stones covering completely deserted 

 galleries, it is probable that the ants keep moving to new nesting sites. 

 This moving must be necessitated by the small amount of moisture in the 

 soil and the rapidity with which it evaporates even from under large stones. 



In the vicinity of Austin, C. wheeleri is not confined to the limestone 

 hills of the Edwards Plateau. On three occasions I found small isolated 

 crater nests of this species in the hard pebbly soil of the open woods at a 

 lower altitude in the outskirts of the town. The exhausted substratum was 

 dumped to one side of the small circular entrance which descended vertically 

 into the soil. These nests must have been much deeper than the ones above 

 described as I never succeeded in excavating them completely or in finding 

 the fungus garden. 



The males and winged females were found in the nests on the Edwards 

 Plateau June 26th, and as early as June 8th in the somewhat warmer country 

 about Fort Davis. In the latter locality I noticed among the vegetable 

 slivers of the exhausted substratum a number of el\i:ra, thoraces, etc., of 

 small beetles', but whether these insects had been collected for food or merely 

 formed a part of the substratum, I am unable to say. 



8. Cyphomyrmex rimosus Spinoia. 



The stations inhabited by the various subspecies and varieties of this 

 widely distributed ant afford a striking contrast with the arid environment 



