The Neotropical species of the ant genus Strumigenys Fr. Smith: group of elongata Roger.

This is a continuation of my series on the species of Strumige nys Fr. Smith from the New World. Previous parts, containing introductory remarks and explanation of the abbreviations for the standard measurements and indices, may be found in Jour. N. Y. Ent. Soc. 61: 53-59 and 101-110 (1953). The present group, after the reduction of three synonyms and the addition of two new species, comprises four known species: S. elongata Roger, S. consanii n. sp., S. ludia Mann and S. pre cava n. sp. The first three of these lack entirely any trace of preapical armament, a character which will separate them from the other groups of the genus found in the New World; S. pre cava does possess a single preapical tooth, but this is short and somewhat modified from the usual spiniform teeth of many other neogaeic species. While the first three species form a tightly-knit group of apparently close relationship, the affinities of S. precava are as close with other groups as with this one. It therefore seems that S. precava may be close to the ancestral stock of the elongata group. If S. precava be included with the elongata group as an arbitrary measure, it becomes clear that it is the most generalized of the species, while S. elongata has un dergone the most radical reduction of mandibular armament and is probably most specialized.