BY THOMAS a. SLOANE. 441 



//rt'i. — Gascoigne River District, W.xV. (Given to me l^y Mr. 

 C. French.) 



A more sombre-coloured species than usual in the genus, the 

 black having a piceous tinge ; in this resembling R. boviUi, Blkb., 

 but differing decidedly from that species in its smaller .size, more 

 depressed f.jrm, differently shaped prothorax with rectangular 

 l)asal angles, and less strongly striate elytra, kc. From R. miser, 

 Chaud., which is about the same size, it may be distinguished by 

 its colour, shorter and more depressed prothorax, more depressed 

 and less strongly striate elytra, &c. I cannot indicate the differ- 

 ences between A', nigellus and Feronm arnhelmensis, Casteln., but 

 consider there is no possil)ility of their Iteing identical. 



Rhytisternus gigas, n.sp. 



^. Oblong, robust ; prothorax transverse, a little narrowed and 

 sinuate on each side towards base, wider across base than apex ; 

 elytra convex, strongly striate {seventh stria only, obsolete 

 towards base), interstices strongly convex ; prosternal episterna 

 smooth (obsoletely subrugulose under a lens). 



Black, shining ; palpi reddish, tarsi piceous. Head large, 

 smooth ; front with two short lightly divergent impressions, and 

 behind each of these another light foveiform impression ; front 

 convex between impressions ; clypeal suture lightly marked ; 

 clypeus strongly declivous to labrum ; eyes convex, lightly set in 

 orbits at base. Prothorax subquadrate, transverse (4-4 x 6 mm.), 

 depressed on disc, roundly declivous to sides anteriorly ; disc 

 faintly transversely striolate ; sides rounded on anterior 'three- 

 fourths, narrowed to anterior angles, lightly narrowed posteriorly, 

 almost straight, but not the least out-turned before base ; anterior 

 margin widely and lightly emarginate ; base sinuate, truncate 

 (hardly oblique) on each side of peduncle, lightly emarginate 

 across peduncle (this median emargination nearly truncate) ; 

 anterior angles rounded, very lightly advanced ; basal angles 

 rectangular, obtuse at summit ; lateral border thick, re flexed ; 

 median line lightly impressed ; two separate lateral basal impres- 

 sions on each side, both attaining base ; the interior rather wide, 

 31 



