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WHEELER. 



developed, produced as a prominent angle. Mandibles triangular, 

 deflected, with nearly straight external and finely denticulate apical 

 borders. Clypeus short, vertical. Frontal carinse erect, not very 

 prominent, rather small, not truncated before their confluence behind. 

 Antennal scapes not more than half as long as the head, gradually 

 incrassated toward their tips, funicular joints 1 and 10 slightly longer 

 than broad, joints 2-9 distinctly broader than long, terminal joint 

 rather swollen and scarcely tapering, a little longer than the two pre- 

 ceding joints together. Thorax a little more than twice as long as 

 broad, as broad through the pronotum as through the epinotum, 

 slightly narrowed in the mesonotal region and with concave meso- 

 pleurse. Marginations developed on the anterior and lateral borders, 

 on the boundary between the epinotal base and declivity, along the 

 sides of the latter and the prosterna. Upper corners of epinotum not 



Figure 16. Phyracaces senescens sp. nov. Worker, a, dorsal view of body, 

 b, antenna of same. 



dentate. In profile the thoracic dorsum is very feebly and evenly 

 convex, the declivity of the epinotum steep and straight. Petiole 

 as broad as the epinotum, rectangular, broader than long, broader 

 behind than in front, with concave anterior, straight lateral and 

 nearly straight posterior border and its posterior angles produced 

 as acute, slightly incurved teeth. The lateral borders are marginute, 

 the anterior border submarginate. In profile the dorsal surface is 

 flat and forms a right angle with the truncated, vertical anterior 

 surface, the posterior surface is concave and slightly sloping, the 

 ventral surface bears a pointed, triangular tooth at its anterior end. 

 Postpetiole broader than the petiole, nearly as long as broad, not very 

 sharply separated ftom the gaster, with roimded dorsal and lateral 

 surfaces and anterior angles. First gastric segment broader than 

 long and decidedly broader than the postpetiole. Pygidium with a 

 shallow elliptical impression on its dorsal surface, its sides beset with 



