BY T. G. SLOANE. 593 



Helluarchus robustus, n.sp. 



Stout, oval, glabrous ; body very large. Black. 



Head large (6-5 mm. across eyes), punctate. Prothorax 

 broader than long (6-3 x 9 mm.) ; sides inflated and rounded at 

 middle, narrowed in a curve to apex, strongly sinuate at pos- 

 terior fourth ; basal angles distant from peduncle, well mark- 

 ed, obtuse; base (6mm.) wider than apex (5mm.); disc 

 sparsely punctate ; lateral margins explanate, punctate. Elytra 

 oval (21x14 mm.), rounded at apex in an even curve, not 

 quite covering apex of abdomen; disc depressed, bordered by 

 the strongly costate fifth interstice ; striae punctate ; interstices 

 sparsely seriate-punctate : punctures small, disposed in two 

 rows on third, fifth, and seventh interstices, more irregular on 

 the others (third interstice raised just before apical declivity, 

 fifth costate, seventh subcostate, the others depressed). Under 

 surface generally more or less punctate ; abdomen convex, 

 sparsely punctate towards middle, strongly punctate towards 

 lateral margins. Length 36, breadth 14 mm. 



Hah. — Western Australia: Anketell, near Cue (H. W. 

 Brown). Colls. Sloane (type) : National Museum, Melbourne; 

 South Australian Museum, Adelaide. 



Genus Gigadema. 



Thomson, Arcan. Ent., 1859, 93; Castelnau, Trans. Roy. 

 Soc. Victoria, viii., 1868, 105; Chaudoir, Rev. & Mag. Zool., 

 1872, 215: Penichrodema Gestro, Ann. Mus. Civ. Genova, 

 vii., 1875, 880. 



Depressed, black; winged. Labrum large; one sensitive seta 

 on each side near anterior angle. Labium variable, always 

 wide and rounded on sides. Mentum with a short median 

 tooth ; lobes short, triangular, pointed (in G. longipenne very 

 long and sharply pointed). Palpi variable; apical joint more 

 or less triangular. Maxillae with inner lobe sharply pointed ; 

 inner side with a median prominence (except in G. longi- 

 penne). Prothorax roundly ampliate at widest part, strongly 

 angustate at base; basal angles near peduncle. Elytra strong- 



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