430 bulletin: museum of comparative zoology. 



A distinct species, characterized by the structure of the mesonotum 

 in the soldier and by the elevated triangular projections at sides of the 

 pro- and mesonotum in worker. 



The colonies found were small ones, situated beneath stones. Type. 

 — M. C. Z. 8,694. 



22. Pheidole umbonata Mayr. 



Sitz. Akad. wiss. Wien, 1866, 53, p. 510, ^ cf (excl. 9%). Verb. Zool. hot. 

 geseUsch. Wien, 1870, 20, p. 977, 978, %. 



Soldier. Length 2.10-2.50 mm. 



Head a little longer than broad, as broad in front as behind, sides moder- 

 ately convex, occipital border broadly and, at middle, rather deeply excised, 

 vertex not transversely impressed. Mandibles with a tooth at the angle 

 between base and blade, bidentate at tip. Cly]3eus flat in front, its anterior 

 border nearly straight. Antennal scapes extending a little less than half the 

 distance to occipital corners; first funicular joint as long as the next three 

 joints together, joints 2-8 a little broader than long; club shorter than re- 

 mainder of funiculus, its terminal joint longer than the otlier two together. 

 Eyes little convex, situated at anterior fourth of head. Pronotum much 

 broader than long, sides submargined and broadly rounded at tips. Pro- 

 mesonotal suture barely distinct. Mesonotum flat. Epinotum shallowly 

 concave between the spines, the base about as long as declivity; spines triangu- 

 lar and acute, shorter than their distance apart at base. Petiole rather short, 

 node in profile higher than long; above, concave at middle with the sides 

 subconical. Postpetiole a little less than twice as broad as petiole, broader 

 than long, broadest in front of middle, with nearly straight sides. 



Moderately shining throughout. Mandibles with fine and regular setiger- 

 ous punctures. Head regularly, longitudinally striate, the striae becoming 

 obsolete on vertex; occiput smooth. Pro- and mesonotum smooth. Epino- 

 tum coarsely, though shallowly reticulate. Petiole, postpetiole, and gaster 

 smooth. 



Fine, erect hairs moderately abundant on head, body, and appendages. 



Brownish yellow, gaster pale fuscous. 



JVorker. Length L25-1.50 mm. 



Head slightly longer than broad, sides feebly convex, posterior corners 

 broadly rounded, occipital border very shallowly concave at middle. Mandi- 

 bles with fine elongate triangulate teeth. Clyijeus straight at anterior border. 

 Antennal scapes slightly surpassing occipital corners; funicular joints 2-8 

 about as long as broad. Eyes large, situated at anterior third of sides of head. 

 Pronotum evenly rounded above and at sides. Promesonotal suture very 



