438 bulletin: museum of comparative zoology. 



blades are distinctly tridentate basally. In the worker of knowlesi 

 the head of the worker is rather strongly punctate at the sides, instead 

 of smooth as in megacephala. Type. — M. C. Z. 8,698. 



27a. Pheidole knowlesi Mann, subsp. Extensa, subsp nov. 



Soldier. Length 3 mm. 



Differing from typical knowlesi only in having the frontal striae extending 

 beyond the transverse vertical impression and on to the vertex, with the inter- 

 spaces distinctly though very finely punctate and the head more uniformly 

 fuscous instead of reddish brown and lacking the darker blotches on the front. 



Worker. Length L75 mm. 



Very similar to that of knowlesi, but with the head between the frontal 

 carinae finely and sparsely striolate longitudinally, and rather sparsely punc- 

 tate. 



Viti Levu: Nadarivatu (Type-locality), Nasoqo. Vanua Levu: 

 Wainunu. 



A harvesting species, very common beneath stones. It is the host 

 of several species of clavigerid beetles. 



The differences in striation between this and the preceding form, 



though slight, are . constant in a large series before me. Type. — 

 M. C. Z. 8,699. 



28. Pheidole (Electropheidole, subgen. nov.) roosevelti, 



sp. nov. Fig. 15. 



Soldier. Length 4.75-6 mm. 



Head one fourth longer than broad, slightly broadened behind, sides nearly 

 straight, posterior corners prominent and rounded, border deeply excised, 

 vertex broadly impressed transversely. Mandibles thick, their blades with a 

 small triangular tooth basally, and two very stout teeth apically. Clypeus 

 impressed in front of middle, then elevated, with the anterior border concave 

 at middle. Frontal carinae no stronger than the other carinae on the front 

 and bordering very poorly defined scrobes. Antennal scapes extending a 

 little more than half the distance to occipital corners, slender and arcuate 

 basally, thickened at apical third; funicular joints 2-8 about twice as long as 

 broad, club very slender, much shorter than remainder of funiculus, with the 

 first two joints subequal and together much longer than the terminal. Eyes 

 small and moderately convex, situated at sides of head in front of anterior 



