AMMOCHyETiE. 



195 



Mexico, Arizona and northern Mexico. We should therefore 

 expect them to have well-developed ammochaetae. These are, 

 in fact, present in both species, but, as shown in Fig. 4, the gular 

 hairs are diffuse and not arranged in an arcuate series. They 

 are, however, longer and more slender than the blunt, white 

 hairs covering the remainder of the body, and are distinctly 

 hooked or curved upward at their tips. This peculiar modifica- 

 tion of the gular hairs is not seen in the other members of the sub- 

 genus inhabiting more humid regions, like I. araneoides Emery 

 of Central America, szvammerdami Forel of Madagascar, and 

 longipes F. Smith of Burmah and Sumatra. In pilosity these 

 resemble our northern species of Aphcznogaster. 



Messor Forel. — This subgenus of harvesting ants is repre- 

 sented by a number of species, subspecies and varieties in Africa, 



Fig. 5- Goniomma blanci, v. tuneticum Forel. 



especially in the Sahara, in southern and central Europe and 

 Asia and by five species in Arizona, Nevada, California and north- 

 western Mexico. In both hemispheres the xerophilous species 

 have well-developed ammochaetae, whereas these structures are 

 small or lacking in the moisture-loving forms. To the latter 

 group belongs the widely distributed M. barbarus L. which even 

 in Africa, according to Forel " vit dans les lieux moins sees ; fait 

 sou vent des nids maconnes dans la terre, dans les prairies, " * 

 and Lameere 2 says : " Je n'ai rencontre le type de cette moisson- 

 neuse que dans les parties cultivees des oasis ; dans le desert cail- 



1 See Emery, "Revision Critique des Fourmis de la Tunisie, in Exploration 

 Scientifique de la Tunisie," Paris, 1891, p. 10. 



2 " Note sur les Moeurs des Fourmis du Sahara," Ann. Soc. Ent. Belg., XLVI., 

 1903, pp. 160-169. 



