NEW FORMICID^E FROM BARRO COLORADO ISLAND. 153 



lying near their nest, but that day they had nothing else; if the 

 choice be left to them they invariably take fruit and seem to 

 prefer the orange among these. Very small particles of the white 

 skin of the oranges are torn off, and, after undergoing a slight 

 kneading process in the ants' mandibles, are placed in the nest. 

 The neutres are all of the same size, varying but slightly and 

 never exceed 4 mm. in length. They are more diurnal in their 

 habits than other species of fungus growers, but also work a 

 little at night. -I have found winged forms in the nests in the 

 month of July." 



The following year Forel, while recording his observations on 

 the Attini of Colombia, published the following remark (1896, p. 

 406): 'The fungus gardens of the large A tta species, of the 

 subgenera Trachymyrmex For. and Mycocepurus For., as well as 

 of the genus Sericomyrmex were previously unknown and were 

 discovered by me. The gardens of the three latter groups seem 

 to resemble those of Apterostigma, and these small ants are never 

 seen on the trees in the act of cutting leaves. They bring into 

 their nests small, desiccated vegetable particles; their fungus 

 garden lies very deep in the earth and is very imperfect." The 

 Colombian species of Sericomyrmex (S. diego Forel) observed by 

 Forel was not described till 1912 (p. 193). He then added the 

 following note: "Don Diego, at the foot of the Sierra Madre de 

 Santa Marta, Colombia, the third of March, 1896, in the forest; 

 nest in the humus, with a crater of coarse granules. A beautiful 

 fungus garden at a depth of 2 decimeters in the earth. The 

 worker feigns death like the species of Cyphomyrmex. They 

 collect little green vegetable particles resembling an alga and 

 make their fungus garden of them and other debris." Essentially 

 the same account was published by Forel in the " Biologia 

 Centrali-Americana" (1899-1900, p. 37). 



It will be noticed that Urich and not Forel was the first to 

 observe the fungus gardens of Sericomyrmex and that the latter's 

 various accounts contain some glaring discrepancies. In one 

 account the garden is described as "very imperfect," in another 

 as "beautiful." Furthermore, he could not have seen the fungus 

 garden of Mycocepurus, which cultivates a peculiar fungus very 

 similar to if not the same as the Tyridiomyces formicarum culti- 

 vated by Cyphomyrmex rimosus (Wheeler, 1907, p. 771). 



