46 Journal New York Entomological Society, t^'o'- xxii. 



rather small size nesting beneath stones at Guerrero Mill. This 

 species is evidently closely related to Ph. floridana, but the head of 

 the soldier is larger, less flattened, the thorax is stouter, with smaller 

 cpinotal spines, the postpetiole is decidedly narrower and the sculp- 

 ture is very different both in the soldier and worker. The worker of 

 chalca, moreover, is much more robust than that of floridana and it 

 various subspecies and varieties, and the pilosity is very dififerent, 

 being like that of the soldier and not consisting of very sparse, 

 feebly clavate hairs on the body. 



i6. Pheidole ceres Wheeler subsp. tepaneca new subspecies. 



Soldier. — -Differing from the typical form from Colorado in the darker 

 color of the head, thorax and gastcr, which are black and not dark brown, and 

 in the sculpture of the head and thorax, especially the posterior lobes of the 

 former and the pronotum, which are more glabrous and shining. The rug^e on 

 the anterior part of the head are sharper and more nearly straight and the 

 interrugal spaces are finely and densely punctate and much less distinctly 

 reticulate. 



Worker and female differing from those of the tj'pical ceres also in their 

 darker color and more shining surface. 



A few soldiers and females and many workers of this harvesting 

 ant were taken from small colonies under stones at Guerrero Mill. 



17. Pheidole (AUopheidole) centeotl new species. 



Soldier. — Length 4 mm. 



Allied to Ph. macclcndoni Wheeler. Head very large, including the man- 

 dibles fully twice as long as the thorax, longer than broad, rather flat, especial'y 

 behind, as broad in front as behind, with straight sides and rounded posterior 

 lobes, separated by a deep angular excision and with a pronounced middorsal 

 groove continued forward to the frontal area. Eyes small, rather flat, at the 

 anterior fourth of the head. Mandibles convex, with two blunt apical teeth. 

 Clypeus very short, carinate, with the posterior margin deeply impressed and 

 the anterior margin narrowly notched in the middle. Frontal area small, tri- 

 angular, rather deeply impressed, with a median carinula. Frontal carinse 

 short, diverging posteriorly. Antennae small and slender; scapes reaching only 

 a short distance behind the eyes, terete, slightly curved at the base, funicular 

 joints 2-8 as long as broad. Thorax small, less than half as broad as the 

 head, with bluntly rounded humeri. In profile the pro- and mesonotum form 

 a single convex mass, the mesonotum having a plain surface, without transverse 

 constriction or welt, sloping to the epinotum, which has a subequal base and 

 declivity, the former horizontal, the latter very sloping, armed with two small, 

 erect teeth, which are as long as broad at the base. Petiole from above fully 

 twice as long as broad, with subparallel sides ; in profile the node is moderately 



