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BY A. M. LEA. 503 



middle of the base so as to form a distinct V. Two specimens, from Western 

 Australia and New South Wales, have the reddish sub-basal markings on the 

 elytra dilated to the base and suture, but, leaving a fairly large, round, dark spot 

 isolated on each side near the base; on a somewhat similar specimen from South 

 Australia the spots are but feeble infuscations, and the punctures on the elytra 

 are rather strongier than usual. Two unusually small specimens, with the elytral 

 derm entirely dark, were taken at Murray Bridge from a nest of the ant, Ponera 

 lutea. 



FOEiiicoiius MASTERSi King. 



Syn.— F. Kingi Macl. 



In general appearance this species is close to large dark specimens of F. 

 quadrimaculatiis , but differs in having the hind femora strongly and unequally 

 bidentate, the teeth being placed side by side, the inner one larger than the 

 outer; the prothorax is usually darker on the anterior sides than elsewhere, and 

 has (on specimens in perfect condition) V-shaped pubescence as on the species 

 named ; there are also two similar, transverse, reddish fasciae on the elytra, in- 

 terrupted before the sutui-e, and clothed with white pubescence, but the sub- 

 basal fascia is usually more distinct than the postmedian one; occasionally both 

 are absent or very feeble, but the clothing covering them appears to be always 

 conspicuous on non-abraded spexsimens. A eotype is in the South Australian 

 Museum, and many specimens from Morgan and other localities on the Murray 

 River. 



Macleay dtescribed the type of F. Kingi as having the hind femora "very 

 strongly toothed on the under-side near the apex." Six cotypes before me are 

 bidentate; the teeth vary somewhat in size on the specimens but one is always 

 smaller than the other; they agree perfectly with South Australian specimens of 

 F. mastersi. 



FOEMICOMUS SPECIOSUS King. 



The head and prothorax (especially the latter) of this species are densely 

 and coarsely punctured, the transvei-se spots or intei-rupted fascia (near the base 

 of the elytra) of silvei-y clothing are jDlaced within depressions, and the hind 

 femora are strongly dentate, the teeth being placed sidei by side as in F. mastersi, 

 from which it may be readily distinguished by the elytra and punctures. A 

 specimen was taken at the Swan River, by Mr. J. Clark, from a nest of the twig- 

 mound ant, Iridomyrmex conifer. 



FORMICOMUS DENISONI King. 



Syn. — F. nigripennis Champ. 



A common species in North Queensland. Although King described the 

 elytra as "nigro-cyaneis" they are nearly always deep shining black, the bluish 

 gloss being very seldom in e\'idence, and the head and prothorax are of a blight 

 red; the legs, especially the front ones, vary somewhat in colour, but (except at 

 the base of the femora) are usually black. The front femora are strongly den- 

 tate in the male, edentate in the female. The length varies from 3.25 to 4.75 

 mm. Some specimens from North Queensland differ from typical ones in being 

 entirely black, except that parts of the mouth are obscurely diluted with red; 

 one has the head, front tarsi and some of the mouth parts of a dull red, all other 

 parts being black. F. nigripennis was described from a small male of the 

 species. 



