A NEW GENUS OF HYPOG/EIC ANTS FROM TEXAS. 147 



pared with workers, especially when we reflect that they repre- 

 sent the sterile and fertile extremes of the same sex. 1 



2. The workers of the species in question all have a pale, 

 etiolated appearance, being uniformly yellow or light brown in 

 color, while the huge males and females are deeply and often 

 conspicuously colored. This is noticeably the case with Care- 

 bar a and Erebomyrma. 



3. The eyes of the workers are vestigial or quite absent (Care- 

 bara], in marked contrast with the well-developed eyes and ocelli 

 of the males and females. 



4. As we should naturally infer from the characters enumer- 

 ated under 2 and 3, these ants are hypogaeic or subterranean, /. c., 

 rarely or never coming to the surface except during the nuptial 

 flight of the deeply colored sexual forms. 



5. It is clear that the diminutive workers must be able to 

 obtain large quantities of food, or they could never raise so 

 many and such enormous males and females. From this, again, 

 we may infer that the species prey on other ants or termites, 

 and this inference is supported by observation in all cases where 

 it has been possible to study these ants in their nests. The 

 European Solcnopsis fugax, the North African 5. latro, the North 

 American 5. molest a and 5. tc.vana, and probably many other 

 small species of the genus, live in the nests of larger ants belong- 

 ing to different genera and species (Formica, Aph&nogaster, etc.). 

 Here they inhabit small chambers in the walls separating the 

 galleries of the larger species and, escaping notice, probably on 

 account of their minute size and neutral nest-odor, prey upon the 

 helpless and well-fed larvae and pupae of their hosts. This mode 

 of life has been recently called " Icstobiosis " by Forel, who has 

 directed attention to similar habits in Aeromyrma and Carebara. 

 Sikora found Aeromyrma Nosindambo Forel, of Madagascar, as a 

 regular inhabitant in the earthen nests of termites, and Haviland 



1 Other cases comparable to the extreme disproportions of the female and worker 

 Carebara are certainly rare but they occur nevertheless in Pheidologeton and in Atta 

 (s. sir. ). The minimum workers of the Texan Atta Jervens Say are barely 2 mm. long, 

 whereas the queens measure fully 17 mm. Among some specimens of the Bengalese 

 Pheidologeton ocellifer Smith given me by Professor Forel, I find diminutive workers 

 only 2.25 mm. long and a queen of 16 mm. The relative differences in volume in 

 these cases can be approximately computed without difficulty 



