82 Psyche [June 



Messor lobognathus sp. nov. 

 Worker: Length, about 6 mm. Head quadrate, about as wide 

 as long, excluding mandibles. Posterior corners of head rounded, 

 vertex almost straight, sides almost straight and parallel. Surface 

 of head with sparse hairs, rugose, with rugae posteriorly divergent; 

 interrugal spaces distinctly reticulate. Clypeus very short with 

 rugose surface, ridges irregular; shallowly emarginate anteriorly. 

 Mandibles stout and convex, peculiarly lobed apically, with two 

 large apical teeth and five to seven rudimentary teeth; surface 

 coarsely striated. Eyes moderate, at sides of head, about half way 

 between clypeus and vertex. Antennae 12-jointed, hairy; scape 

 compressed and dilated at base, hardly extending beyond corners 

 of head; last four joints of funiculus incrassate, but hardly form- 



Messor lobognathus sp. nov. Lateral view and anterior view of head. 



ing a distinct club. First joint longer than second, but not twice 

 as long. Pronounced beard of recurved hairs, as in Pogonomijrmex. 

 Thorax slender, irregularly rugose, sparsely clothed dorsally with 

 long, glistening, light yellow hairs. Pro- and meso-notum convex. 

 Thoracic dorsum deeply impressed at mesoepinotal suture; meso- 

 epinotal suture distinct. Spines of epinotum acute, much longer 

 than broad at base; divergent; striations radiating from the base; 

 infraspinal cavity smooth. Petiole punctate with a few hairs; 

 longer than wide; ventral surface straight in profile; a high pos- 

 teriorly placed superior node; apex broader than base; posterior 

 slope abrupt; anterior slope long and gentle. Postpetiole narrow 

 at base, a little longer than wide when seen in profile; superiorly 

 convex and sides rounded. Thus the postpetiole is globose. Gaster 

 shining, scarcely larger than head, with delicate microscopic re- 

 ticulate sculpture on apical part of segments. Sting vestigial. 

 Legs quite long; posterior tibial spurs spinulose. 



