Pogonomyrmex snellingi

Known from the type collection, taken from low elevation sand dunes in Baja California, Mexico, and a second collection from Baja California Sur. This second collection was found in the Vizcaino Desert and was made from a tumulus nest with 2-3 entrances.

Identification
Taber (1998) - The oblique dentary margin of the mandible (similar to that of Hylomyrma) is sufficient for the identification of this species, as all congeners have a roughly transverse margin. Furthermore, no other Pogonomyrmex species has the following combination of characters: distinct gap between the ultimate and penultimate mandibular teeth, offset ultimate tooth, short basal mandibular margin, and circumocular whorls. The oblique dentary margin and the presence of circumocular whorls readily distinguish this ant from both Pogonomyrmex apache and Pogonomyrmex occidentalis.

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Nomenclature

 *  snellingi. Pogonomyrmex snellingi Taber, 1998: 169, fig. A4 (w.) MEXICO.

Description
CI 114.3, EL 0.46 mm, EW 0.28 mm, HL 1.47 mm, HW 1.68 mm, 0I 31, PNL 0-49 mm, PNW 0.35 mm, PPL 0-49 mm, PPW 0.60 mm, SI 75, SL 1.26 mm, WL 1.82 mm.

Mandible with seven teeth; apical tooth longest; subapical about equal in length to first basal; second basal (middle tooth) half or less than half the length of first basal; third basal a little longer than subapical and first basal; penultimate tooth length less than or equal to second basal; ultimate tooth strongly offset, about equal in length to subapical, separated from penultimate tooth by a large gap; basal margin of mandible short and almost straight. Dentary margin of mandible not transverse as in all congeners, but oblique, as in Hylomyrma. Base of antenna moderately developed, but rather large for a member of the P. californicus species complex; basal flange thin; lip weak and curved distad; point weak. Longitudinal cephalic rugae diverging from frontal lobes to occiput, coarseness and spacing of cephalic rugae moderate in comparison with the extremes displayed within the genus; interrugal areolation distinct but not presenting a beaded appearance; circum ocular whorls present (common feature in P. californicus complex); in lateral view, eye situated approximately in the center of the side of the head; frontal area shallow; lateral lobe of clypeus without projection below antenna fossa. MesopropodeaI depression weak, propodeum with small tubercles, but no spines; rugae of thoracic dorsum coarse, interrugal spaces shining; apex of petiolar node rounded, nipple absent; ventral process of anterior peduncle of petiole weak, the process lacking setae (setae present in P. barbatus species complex); ventral process of postpetiole node weak; dorsal rugae of petiolar node sparse and confined to posterior half, surface of node shagreened; a very few rugae on dorsum of postpetiolar node, these confined to extreme posterior of node, the surface of the node shagreened. Dorsum of gaster very lightly shagreened. Setae of head, ali trunk and gaster coarse and clear; psammophore well developed. Body color dark reddish brown.

Paratypes: CI 100.0- 119.0, EL 0.35-0.42 mm, EW 0.25- 0.28 mm, HL 1.47- 1.65 mm, HW 1.65-1.75 mm, 01 23.4- 26.7, PNL 0-46- 0.53 mm, PNW 0.35-0.39 mm, PPL 0.42....:.0.49 mm, PPW 0.56-0.63 mm, SI 62.7- 65.2, SL 1.05- 1.I2 mm, WL 1.75-1.89 mm.

The propodeal armature varies from very short spines to a complete absence of either spines or tubercles. The paratypes are otherwise similar to the holotype.

Type Material
HOLOTYPE (worker): Mexico, Baja California, 8 km N Guerrero Negro, altitude 0- 8 m; sand dunes, 24 August 1977, R. Snelling (collector). PARATYPES (worker): Five specimens, with same collection data as holotype. LACM,, , Taber personal collection

Etymology
The new species is dedicated to Roy R. Snelling, accomplished hymenopterist and collector of the ant named in his honor.

References based on Global Ant Biodiversity Informatics

 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Johnson R.A., R.P. Overson and C.S. Moreau. 2013. A New Species of Seed-harvester Ant, Pogonomyrmex hoelldobleri (Hymenoptera: Formicidae), from the Mohave and Sonoran Deserts of North America. Zootaxa 3646 (3): 201-227
 * Johnson, R.A. and P.S. Ward. 2002. Biogeography and endemism of ants (Hymenoptera: Formicidae) in Baja California, Mexico: a first overview. Journal of Biogeography 29:10091026/
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133