472 bulletin: museum of comparative zoology. 



56a. Iridomyrmex nagasau Mann, subsp. alticola, subsp. nov. 



Worker. Length 3.75-5 mm. 



Differing from typical nagasau in having the basal portion of epinotum less 

 elevated, sloping and more broadly rounding into the declivity, and in color, 

 the head being uniformly reddish brown and the thorax somewhat hghter. 



Taviuni: Nagasau, near Lake. 



A series v^as taken from several colonies in Myrmecodia bulbs at 

 the edge of the swamp that surrounds the crater-lake in the interior. 

 Tijpe.— M. C. Z. 8,714. 



56b. Iridomyrmex nagasau Mann, subsp. agnatus, subsp. nov. 



Worker. Length 3-4 mm. 



Differing from I. nagasau nagasau in its smaller size, the base of epinotum 

 lower and more sloping (as in subsp. alticola) and in being brown in color, with 

 the gaster slightly darker than the rest and the tarsi white. 



VanuaLevu: Wainunu. 



Described from several workers found running on tree-trunks. 

 Type.— M. C. Z. 8,715. 



57a. Iridomyrmex anceps Roger, subsp. ignobilis, subsp. nov. 

 Worker. Length 2.75 mm. 



Head a third longer than broad, narrowed in front, sides convex, posterior 

 corners and border broadly rounded. Mandibles elongate, with six rather 

 stout, triangular teeth. Clypeus convex, anterior border straight. Antennae 

 slender, scapes surpassing occipital borders by about one third their length; 

 funicular joints all more than twice as long as broad, decreasing in length 

 toward apex, terminal joint two thirds as long as the two preceding joints 

 together. Eyes large, and feebly convex, situated in front of sides posterior 

 to middle of head. Pronotum longer than broad, moderately convex above. 

 Mesonotum much longer than broad, rather flat. Epinotum in profile convex, 

 not elevated, the base and declivity broadly rounding into each other. Node 

 thickly squamiform, little narrowed above; seen from behind, about twice as 

 high as broad and rounded above. Legs very long and slender. 



Moderately shining. Mandibles basally with square, coarse punctures. 

 Head, body, and appendages finely, densely, and shallowly punctate. 



