New forms of Odontoponera transversa

Odontoponera was first recognized as a distinct genus in 1862 when Mayr raised to generic rank an ant described a year earlier by Frederick Smith as Ponera denticulata. This insect was later found to be identical with Smith's Ponera transversa described in 1857. The name denticulata was, therefore, replaced by transversa. Although the single species by which this genus is represented is fairly abun- dant and distributed throughout many of the islands of the East Indies and the adjacent portions of the continent, little attention has been paid to its variations. Wheeler and Chap- man in 1925 described biconcentrica, a variety from the Philippines but except for this no other form has been noted. Dr. W. M. Wheeler has kindly permitted me to ex- amine the Odontoponera material in his collection and I find that it is possible to recognize two additional variants. One of these is plainly of subspecific rank while the other appears to be a color variety of the typical transversa. Biconcentrica must, I believe, be raised from varietal to subspecific status.

The shape and the sculpture of the node of the petiole which appear at first sight to offer striking characters for separation are quite valueless in this regard. In a series of workers from a single nest the petiole may be narrow with a deeply notched summit and heavy rug= on the basal half or relatively broad with the notch and rug= reduced or absent. The same is true to a lesser degree of the sculpture of the pronotum. This usually consists of more or less pa- rallel, heavy, transverse rugae. Occasionally, however, one or two workers in a series have the posterior pronotal rug= twisted into two whorl-like configurations. As may be recal- led this characteristic formed the basis for the recognition Contributions from the Entomological Laboratory of the Bussey Institution, Harvard University, No. 315.