28 William Morton Wheeler 



carina parallel with the frontal carina, but shorter. Eyes large, round, 

 convex, consisting of many minute ommatidia. Antennae short, 

 12-jointed, scape thickened distally, funiculus not ending in a one- 

 jointed club, the last being shorter than the two preceding joints toge- 

 ther. Thorax rather short, cylindrical, without promesonotal or meso- 

 epinotal sutures or depressions. Petiole stout, barrel -shaped, with a 

 prominent, compressed anteroventral tooth. Postpetiole much larger 

 than the petiole, separated by a pronounced constriction behind from 

 the gaster. The latter is short and compact, without constrictions 

 between the segments; its first segment longer and broader than the 

 petiole, remaining segments very short, convex above and apparently 

 somewhat deflected. Legs rather stout; all the tibiae with well-developed, 

 pectinated spurs. Genotype: P. annosus sp. nov. 



ProceraiMcliys differs from Cerapachys in the structure of the 

 antennae, which do not terminate in a one-jointed, glandiform club, 

 and have longer and more uniform joints, much as in certain species 

 of Eciton. From Sphinctoniyrmex it differs in the structure of the 

 abdomen which is much shorter and not constricted behind each segment. 

 From Lioponera it differs in its heavy sculpture. In most of these 

 characters and in the rather large size of the species, the new genus 

 is of a more primitive type than its modern representatives. Its 

 occurrence in the amber is of great interest because it shows that the 

 Cerapachyini, now confined to the tropics and most abundantly re- 

 presented in the Indian and Australian regions, had a much wider 

 distribution during Oligocene times. 



JProcerapachys annosus, sp. nov. 

 Worker (Fig. 2a and b). Length 6 — 7,5 mm. 



Head, excluding the mandibles, slightly longer than broad, a little 

 broader behind than in front, with rather straight, subparallel sides, 

 and, when seen from the front, with straight posterior border; seen 

 from above the occipital border is broadly excised and on each side 

 of it the head has a bluntly angular projection. Antennal scapes 

 reaching to the eyes; joints 1 — 10 of the funiculus somewhat broader 

 than long, terminal joint rather pointed, a little longer than broad. 

 Ocelli sometimes present. Thorax cylindrical, slightly constricted behind 

 and convex in the pleural region, a little more than twice as long as 

 broad, slightly narrower than the head, Pronotum with a prominent 

 transverse ridge behind the very concave neck, A similar ridge forms 

 a border to the whole epinotal declivity, which is very flat and abrupt. 



