1911] JJlieeler — New Ants from Mexico and Central America 207 



Female. Length 4.5 mm. 



Closely resembling the worker, but with the neck like posterior portion of the 

 head much longer and the eyes larger. Mesonotum above with four longitudinal 

 welts, the two lateral of which are short and feeble and cover the paraptera, while 

 the two median are longer. Scutellum behind bearing two flat, blunt teeth which 

 are as long as broad at their bases. Epinotum in profile with subequal base and 

 declivity, both flattened and meeting to form an obtuse angle. Seen from above 

 the base bears a pair of longitudinal ridges like those of the worker. 



Sculpture, pilosity and color as in the worker. The hairs are, perhaps, shorter 

 and more appressed on the head and thorax. Wings opaque, gray, with yellow 

 stigmal region and two sharply defined, elongate black spots, one at the base and 

 the other between the two branches of the cubital vein. 



Described from twelve workers, one dealated and five winged 

 females taken by Dr. P. P. Calvert from two colonies in the Banana 

 River District and Juan Viiias, Costa Rica, during October and 

 November, 1909. Both the colonies from which the specimens 

 were taken had constructed their fungus-gardens between the 

 overlapping leaves of Bromeliads growing on trees 10-15 feet 

 above the ground. One of the Bromeliads was also tenanted by 

 a caterpillar and the larva of an interesting dragon-fly (Mecisto- 

 gaster modestus). Fragments of one of the fungus-gardens, pre- 

 served in alcohol with the ants, seemed to present the same primi- 

 tive development of the hyphal swellings ("ambrosia") growing 

 on a substratum of insect (beetle .f*) excrement as described by 

 Moeller for some of the South American species of Apterostigma. 

 The gardens of all previously described species of this genus have 

 been found either in rotting wood or under stones. The unusual 

 situation of the gardens of the new species may account for its 

 having been overlooked by the many diligent collectors of Central 

 American Formicidse. 



A. calverti is most closely related to A. wasmanni Forel, but 

 differs in its much darker color, coarser sculpture and pilosity, in 

 the shorter backward continuations of the frontal carinse, and in 

 lacking the longitudinal lateral ridges on the first gastric segment. 

 The following table will serve for the identification of the workers 

 of the known species of the genus, with the exception of the Mexi- 

 can A. scutellare, which is known only from a single male speci- 

 men: 



1. Head gradually constricted behind into a narrow neck, which has a 



distinctly reflected or expanded posterior edge 2 



