Crematogaster quadriformis Roger ^HNS 1863a.

Crematogaster quadriformis Roger ^HNS 1863a: 207.

Crematogaster quadriformis var gracilior Forel ^HNS 1901c. NEW SYNONYMY . [w syntypes examined, MHNG; São Paulo, Brazil]

Crematogaster quadriformis subsp. vezenyii Forel ^HNS 1907b: 25. NEW SYNONYMY .

Crematogaster quadriformis r gracilior Forel ^HNS. Forel 1912c: 218.

Crematogaster (Orthocrema) quadriformis Roger ^HNS. Santschi 1918: 182.

Crematogaster (Orthocrema) quadriformis subsp. gracilior Forel ^HNS. Emery 1924a: 135.

Crematogaster (Orthocrema) quadriformis subsp. vezenyii Forel ^HNS. Emery 1924a: 135.

Crematogaster (Orthocrema) quadriformis gracilior Forel ^HNS. Kempf 1972: 88.

Crematogaster (Orthocrema) quadriformis vezeneyii Forel ^HNS. Kempf 1972: 89.

Crematogaster quadriformis ^HNS is the most frequently recorded ground-nesting Crematogaster ^HNS in Paraguay. This species can be diagnosed by the following combination of character states: propodeum in profile only slightly or not at all depressed below level of mesonotum; propodeal spines elongate but shorter than length of petiole; antennal scapes equal or greater in length than head length, in repose well exceeding the posterior margins of the head in full-face view; head sculpture densely punctate/striate except for a smooth frontal strip;>20 subdecumbent to suberect setae on the first gastric tergite. Crematogaster quadriformis ^HNS shows considerable variation even within nest series in overall size, pilosity, eye size, and extent of punctation/striation on the head.

Jack Longino examined some recent Paraguayan collections and confirmed the identity of this species as C. quadriformis ^HNS. I have subsequently viewed Forel’s types of C. quadriformis gracilior ^HNS from São Paulo and found them to fall well within the range of variation I have observed in Paraguay, so I synonymize C. gracilior ^HNS here.

I was not able to view Forel’s types of C. quadriformis vezenyii ^HNS, described from material collected in Asunción . Forel’s description notes small size, a more shiny head, and lack of a well-developed tooth in the propodeal suture. These character states are common in the C. quadriformis ^HNS material I have examined towards the small end of the size distribution of nest series, so I find it likely that C. quadriformis vezenyii ^HNS is a collection of a young nest or small workers of C. quadriformis ^HNS.