Cephalotes chacmul

Identification
A member of the texanus clade differing from its sister species, Cephalotes auriger, by the thin, appressed hairs on the first gastral tergite of the worker of auriger.

Distribution
This taxon was described, and is only known, from Mexico.

Nomenclature

 *  chacmul. Cephalotes chacmul Snelling, R.R. in De Andrade & Baroni Urbani, 1999: 611, figs. 286, 287 (s.w.) MEXICO.

Worker
Snelling (in de Andrade and Baroni Urbani 1999) – Measurements (mm): HW (greatest head width below the eyes) 0.84-0.89, HL (greatest length from the lower margin of the frontal lobes to the highest level of the margin of the vertex) 1.03-1.06, TL 3.4-4.0.

Head. About 1.2 times longer than broad. Lateral margins slightly divergent above, distinctly reflexed adjacent to eyes; dorsolaterad corners elevated and more or less crenulate; vertexal margin thin and cariniform, very weakly concave in frontal view. Front of head gently convex, with irregularly spaced fine foveolae and with fine, widely spaced longitudinal rugulae, especially across vertex and along sides. Gena and gulae area dull and with coarse longitudinal rugae. Foveae each with appressed, glittering scale-like seta; margins of head with short, erect, simple setae.

Mesosoma. Anterior margin of pronotal disc nearly straight; humeral angle distinct; side with three distinct spines, posterior spine shorter and with apex bluntly rounded or truncate. Mesoscutum with short, acute spine at side. Side of basal face of propodeum with three spines of variable length, mid spine sometimes bluntly rounded. Entire dorsum dull and with relatively coarse longitudinal rugae (partially replaced at sides by elongate setose foveae) that extend onto posterior slope of propodeum. Side of pronotum with curved longitudinal rugae on upper two-thirds or more; remainder of pronotal side irregularly roughened; mesepisternum and side of propodeum with much finer, irregular, longitudinal rugulae. Legs as in major.

Petiole with vertical anterior face, its summit cariniform and with two short submedian teeth; dorsal face with coarse, irregularly longitudinal setose foveae; lateral spines narrow and acute, slightly curved distad. Postpetiole disc with coarse elongate setose foveae; lateral spines similar to those of petiole but slightly broader and longer.

Metasomal tergum 1 invaginated at postpetiolar attachment and distinctly marginate anterolaterally, corner narrowly lamelliform. Disc of tergum 1 dull, weakly striate and with scattered setose foveae; sternum 1 dull, distinctly longitudinally striate at sides, middle one-third to one-half smooth and shiny.

Color blackish, appendages dark brownish; frontal lobes and mesosomal spines translucent yellowish; tibiae and tarsi reddish to yellowish; tergum 1 with anterolateral yellow spots.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 3.28-4.24; HL 0.84-0.96; HW 0.88-1.04; EL 0.24-0.28; PW 0.78-0.96; PeW 0.46-0.56; PpW 0.52-0.64; HBaL 0.30-0.35; HBaW 0.07-0.09; CI 104.7-108.3; PI 108.3-112.8; PPeI 169.5-171.4; PPpI 150.0; HBaI 23.3-25.7.

Soldier
Snelling (in de Andrade and Baroni Urbani 1999) – Measurements (mm): HW [greatest head width below the eyes] 1.48 (holotype), 1.48-1.55 (paratypes), HL (greatest length from the lower margin of the frontal lobes to the highest level of the margin of the vertex) 1.52 (holotype), 1.52-1.61 (paratypes), TL 5.2 (holotype), 4.9-5.4 (paratypes).

Head with complete frontal shield, about 1.05 (1.02-1.04) times as long as wide; margins of shield more strongly reflexed at sides, nearly straight across mid one-third of vertexal margin; dorsolateral corners of head thin and slightly reflexed, clearly visible in anterior view. Foveae of disc about 0.03-0.05 mm diameter, mostly separated by less than one-half fovea diameter, but with some interspaces greater than fovea diameter; interspaces slightly shiny and with numerous micropunctures, each fovea with one appressed, glittering scale-like seta that does not extend beyond fovea margin. Lateral margins of disc with sparse, short, erect, subspatulate setae; similar, but slightly longer, setae present along margins of posterolateral corners. Gular surface shiny between sparse foveae, each with glittering scale-like seta.

Mesosoma. Transverse pronotal carina distinct, somewhat irregular, broadly interrupted in middle; pronotal humerus absent; scapular angle acute; side of pronotal margin, in dorsal view, slightly sinuate and convergent distad, reentrant angle broadly rounded. Side of mesoscutum distinctly projecting as short, rounded lobe. Side of dorsal face of propodeum with short basal tooth; long, slightly curved blunt spine at mid length, and blunt posterior tooth. Dorsal face of propodeum short and abruptly rounded into posterior face.

Pronotum, anterior to transverse carina, slightly shiny between irregularly spaced foveae that become crowded laterad; remainder of pronotal dorsum and all of mesoscutum similar but foveae consistently denser; dorsum of propodeum dull, foveae deeper, contiguous and tending to be linearly arranged. All dorsal foveae with glittering scale-like, appressed setae. Side of pronotum with scattered foveae, mostly along posterior one-half, foveae smaller than those of dorsum and many without setae; mesepisternum dull, roughened, with scattered fine foveae and some irregular longitudinal rugulae. Side of propodeum dull, with irregular, widely spaced longitudinal rugulae; posterior face dull, without rugulae.

Procoxa, in lateral view, with large, robust conical process near base. Femora fusiform, without dorsal angulation.

Petiole with vertical anterior face; dorsal face shorter than anterior face, dull and roughened; lateral spines prominent, acute, and slightly curved caudad. Postpetiole strongly convex, dull and roughened, with setose foveae; lateral spines longer and thicker than those of petiole, acute and slightly curved caudad.

Gaster. Base of tergum 1 distinctly invaginated at postpetiolar attachment; distinctly marginate anterolaterally; disc dull and contiguously micropunctate and with sparse, shallow foveae, each with appressed glittering seta; basal one-third with weak, widely spaced longitudinal rugulae. Sternum 1 dull, contiguously micropunctate, and with some weak, longitudinal rugulae, especially at sides.

Dorsum of mesosoma and disc of metasomal tergum 1 with sparse, erect setae about 0.05 mm long; gastral segments also with longer marginal setae.

Color dull blackish; legs more brownish; cephalic shield translucent reddish-brown anterolaterally; gastral tergum 1 with large anterolateral yellowish spots.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.98-5.32; HL 1.28-1.40; HW 0.88-1.04; EL 0.28-0.32; PW 1.40-1.44; PeW 0.55-0.61; PpW 0.65-0.72; HBaL 0.32-0.36; HBaW 0.08-0.09; CI 108.6-109.4; PI 100.0-105.5; PPeI 229.5-254.5; PPpI 200.0-215.4; HBaI 22.2-25.0.

Type Material
Holotype soldier from Reserva Sian Ka'an, km 11, Sabana, (Quintana Roo, Mexico) 3-4 June 1986, A. Dejean, from pseudobulbs of Tillandsia balbiciana (Bromeliaceae) ; paratypes four soldiers and nine workers, same data as the holotype, three paratypes deposited in, three in and the remaining nine in LACM.

Etymology
Chacmul is the name of the Mayan jaguar god used here as specific name in apposition.