Pheidole in the New World. A dominant, hyperdiverse ant genus. Author Wilson, E. O. text 2003 Harvard University Press Cambridge, MA http://atbi.biosci.ohio-state.edu/HymOnline/reference-full.html?id=20017 book 20017 Pheidole petrensis new species Types Mus. Comp. Zool. Harvard. Etymology Gr L petrensis , at a stone, alluding to the microhabitat of the type colony. diagnosis A member of the fallax group similar to haskinsorum , hector , lattkei , and susannae , distinguished as follows. Major: head subrectangular in full-face view; tip of antennal scape just reaches occipital comer; almost entire head, mesosoma, and waist foveolate and opaque; entire central strip of all the gastral tergites shagreened and opaque; rugoreticulum limited to space between eye and antennal fossa; carinulae limited mostly to anterior half of head, absent from rest of body; propodeal spines moderately long and thin. Minor: propodeal spines long, very thin, needle-like; head capsule in full-face view forms almost perfect oval; nuchal collar present; entire head and body foveolate and opaque; entire central strip of first gastral tergite shagreened and opaque to subopaque. Measurements (mm) Holotype major: HW 1.16, HL 1.26, SL 1.02, EL 0.22, PW 0.62. Paratype minor: HW 0.68, HL 0.84, SL 1.06, EL 0.20, PW 0.46. color Major: body and appendages medium to dark brown; a darker brown circular spot is present on vertex. Minor: body concolorous light brown. Range Known only from the type locality. Biology Collected from beneath a rock. A male was present in the nest on 26 May. Figure Upper: holotype, major. Lower: paratype, minor. MEXICO: 24 km west of Cuernavaca, Morelos, 2200 m (William P. MacKay). Scale bars = 1 mm.