132 
decidedly separate it. It also resembles &. callabonnensis, Sl., but 
may be readily distinguished by its larger size, more depressed 
form, and the shape of the prothorax, which is broader, more 
quadrate, and strongly sinuate behind, with much more prominent 
basal angles. 
Named in memory of the greatest explorer of Central Aus- 
tralia, John McDouall Stuart. 
RHYTISTERNUS CALLABONNENSIS, 2. Sp. 
Oblong, depressed ; prothorax subcordate, base (3 mm.) a little 
wider than apex (2°75 mm.), basal angles obtuse, but marked ; 
elytra with four inner striz impressed, the interstices flat; ven- 
tral segments strongly rugulose-punctate. Black, shining ; tarsi 
and palpi reddish-brown ; antennz piceous. 
Male. Head moderate, convex; frontal impressions short, 
strong, diverging backwards, connected in front by the clypeal 
suture; clypeus strongly declivous to labrum; eyes prominent. 
Prothorax transverse-cordate (2°9 x 3:9), widest a little behind 
anterior marginal puncture, convex towards sides ; disc depressed 
posteriorly, obsoletely transversely striolate; sides rounded, 
lightly subsinuate before basal angles; anterior margin emar- 
ginate ; base subtruncate (hardly emarginate) across peduncle, 
sloping forward to the basal angle on each side ; anterior angles 
obtuse, rather more prominent than usual in the genus; basal 
angles obtuse; lateral border narrow, thick; lateral channel 
ending posteriorly considerably before the base; median line 
lightly impressed ; two lateral basal impressions placed in a wide 
depression on each side; internal deeply impressed, lightly 
arcuate ; external shorter, arcuate, parallel with lateral margin 
posteriorly ; space between internal impressions depressed, but a 
little convex, that between external impression and margin con- 
vex anteriorly, not raised above lateral border posteriorly, bear- 
ing at its base a foveiform setigerous puncture. Elytra oval 
(8 x 5 mm.), shortly narrowed to humeral angles, subconvex 
(disc depressed) ; sides subparallel; base truncate ; apical curve 
decidedly sinuate on each side; four inner strie strongly im- 
pressed, simple, entire, fifth, sixth and seventh obsolete, except 
near apex ; four inner interstices flat, hardly convex (sometimes 
a little convex); basal border forming a decided, though obtuse, 
prominence above its junction, with lateral border at humeral 
angle. Prosternum truncate at base, widely transversely im- 
pressed just before basal margin. Ventral segments closely 
punctate; the puncturation coarse near sides, fine but continuous 
across middle. 
Length, 13°3; breadth, 5 mm. 
