760 Bulletin American Mvscum of Natural History. [Vol. XXIII, 



workers, is surmounted by a very flat and obscure crater about 30 cm. in 

 diameter with an oblique and somewhat eccentric orifice 5-10 mm. in 

 diameter. The ants collect buds, small flowers, bits of dead and living 

 leaves and caterpillar excrement as a substratum for their fungus gardens. 

 When rudely touched the workers fall over and "feign death." At first I 

 was inclined to believe that this species is restricted to the sandy seabeaches, 

 but on walking inland about two miles from All Saint's Rectory at Man- 

 grove Key, I found it nesting also in clearings among the 'coppets' wherever 

 a small amount of rich black soil in the cavities of the rough ^olian limestone 

 had induced the negroes to plant maize and other vegetables. Here the 

 ants were busily engaged in cutting and carrying into their nests bits of the 

 green maize leaves after the manner of the species of Atta s. str. In other 

 places, like Fort Charlotte, on New Providence Island, the ants were nesting 

 in the dry shady 'coppets.' In all of these localities the nests extended 

 down through holes or crevices in the limestone, so that I was unable to 

 obtain a satisfactory conception of their structure. 



On a recent trip to the Island of Culebra, a few miles east of Porto Rico, 

 I again encountered this ant but under conditions more favorable for study. 

 The vegetation on Culebra, which is too low to intercept the rain-laden 

 trade winds from the Atlantic, is decidedly xeroph}i:ic. There is no stand- 

 ing water on the island and the short arroyos dry up very soon after a shower. 

 A number of colonies of T. jamaicensis were found in the shade of the trees 

 on the banks of these arroyos. The colonies, at the time of my visit (March 

 2-9), were in an opulent condition and each comprised numerous larvfe, 

 pupae and winged males and females in addition to about a hundred workers. 

 Externally the nests, though in black friable soil, were like those on the sandy 

 beaches of the Bahamas. Their subterranean structure closely resembled 

 that of the simplest, two-chambered nests of septentrionalis. The entrance 

 descended into the soil obliquely and at a distance of 2-3 cm. below the 

 surface, widened into a small spherical chamber 2.5 cm. in diameter. This 

 chamber contained no fungus garden but only a few workers apparently 

 engaged in comminuting leaf clippings and caterpillar excrement. A second 

 gallery 5-10 cm. in length led off obliquely from the bottom of this chamber 

 and terminated in a larger spheroidal cavity 6.5-9 cm. in diameter, filled 

 with a flourishing fungus garden of coarse and nodular structure and sus- 

 pended from rootlets. The brood, callow and recently matured sexual 

 forms were ensconced among the pendent folds and strands. The mycelium 

 was of a bluish color, like that of septentrionalis, with hyphee .58 /< in diameter. 

 The bromatia measured .36 mm. and consisted of well-developed pyriform 

 gongylidia 4-4.6 p. long and 1.5-3 /< broad. 



