150 



bulletin: museum oi comparative zoology. 



middle, humeri projecting and bluntly angulate, lurfaoe Oat, except I 

 shallow ly concave portion at the middle of anterior fourth, sides oearl) straight, 

 converging behind to basal portion of declivity which if lc>^ than halt as b 

 aa the front margin. Base of declivitj with two pairs of triangular spinet the 



anterior of which arc less than half as long as their distance apart at base, the 



posterior pair a little longer and less widely separate.!; surface between the 

 spines concave, strongly declivous to the declivity of epinol urn which is broader 

 than the base, twice as broad as long, flat above, with rather strong margins 



In. 17. — Arehaeomyrmev cacabau Mann. a. Dorsal view of thorax and petiole. 

 Lateral view of tliorax and petiole. C. Front view of head. 



h. 



laterally. Petiole from above subquadrate, a little longer than broad; in 

 profile slightly longer than high, dorsal surface Hat, a little longer than posterior 

 face, bituberculate apically, posterior face with two tubercules, similar to 

 those above but more approximated. Postpetiole twice as broad as long, 

 broadesl in front, with the anterior border straight and elevated into a strong 

 margin; anterior surface flat, (laster very short and broad, firsl segment 

 only visible from above, concave at basal border, broadesl at posterior third. 

 Legs stout. 



Shining. Mandibles punctate, middle portion of clypeus very smooth and 

 shining. Head with regular costate striae which are straight on the front and 

 evenly curving on the sides and vertex, posterior corners smooth and shining. 

 Thorax above with a series of eleven stronger longitudinal costae, which termi- 



