MANN: ANTS OF THE BRITISH SOLOMON ISLANDS. 357 



84a. Strumigenys antaeus Mann, var. fuscior, var. nov. 



Worker. Length 2-2.25 mm. 



Differing from the preceding in its smaller sme and in coloration, being 

 reddish brown, with the gaster, except the apex much darker than the rest of 

 the body. 



San Cristoval: Pamua. Ugi: Pawa. Malaita: Auki. 



Szabo (Ann. Mus. nat. Hung., 1910, 8, p. 368) states that Biro found 

 in New Guinea large and small workers of S. loriae Emery, in the same 

 nest, indicating polymorphism in the species. The specimens that I 

 have separated from aniacus as the variety fuscior certainly are very 

 similar in structure to the type form, but they were found always in 

 separate colonies, the larger and smaller forms never together. I have 

 seen no specimens intermediate in size between the two. 



85. Rhopalothrix isabellae, sp. nov. 



Worker. Length 3 mm. 



Head about as long as broad; strongly excavated behind and with obtusely 

 angulate corners; oblique portions of sides with straight margin. Clypeus 

 narrowed behind and broadly and shallowly concave in front; the suture 

 separating it from the front shallow and rather poorly defined. Mandibles 

 strongly constricted at basal third and much more slender than in the related 

 species. Antennal scapes at base about a third as 

 broad as long; funicular joints two _ and three only 

 slightly transverse, joints three and four longer than 

 broad, terminal joint longer than the four preceding 

 joints together. Pronotum shallowly impressed at 

 middle and obtusely gibbous on either side; humeral 

 angles rounded, without any indication of tubercles. 

 Promesonotal suture obsolete. Mesonotum slightly 

 convex in front, and depressed behind. Mesoepinotal 

 suture distinct. Base of epinotum strongly impressed ^ „^ r.. , ,. ■ • 



, ^ . o J I pjg gg — Rhopalothrix isa- 



mesally, marginate at sides of impression, separated bellae Mann. Worker, 

 from the concave declivous portion by an acute margin; Front view of head, 

 spines short and obtuse apically, their bases extended 



as narrow lamellae along borders of declivity. Petiolar node longer than broad, 

 slightly broadest apically and very feebly convex at sides and front; flat above; 

 about as long as peduncle. Postpetiole one and a third times broader than 

 long, narrowed in front, sides little convex; dorsal surface with a faint medial 

 impression which terminates in front in a broad and shallow fovea; strongly 



