J5Q ANNALS OF THE QUEENSLAND MUSEUM. 
Dimensions-. 14x8 mm. 
Habitat : Sea Lake, Victoria. 
The strong punctures on the elytra, the depressed suture 
through the greater parti of its length, the bisinuate sides of 
prothorax, with the strongly produced anterior angles, differ- 
entiate this species from 0. acuticollis. The punctures are more or 
less arranged in rows between the sub-obsolete costa?, but are not 
in definite lines, and are much larger than in any hitherto described 
species of the genus. 
OKOSTERRHTJS SdTJAMOSUS u.sp. 
Widely elongate-ovate, convex upper surface opaque-brown, 
clothed with short, squamosa, rust-coloured hair, underside nitid 
black, palpi reddish, tarsi and inside of tibiae clothed with red 
tomentum. Head — Labrum very prominent, epistoma sub-truncate 
(a little incurved at middle), rounded at sides, making a wide 
angle with eanthus, the latter widely rounded and very little 
raised, epistoma separated by a deep transverse impression, front 
rather flat, whole surface (where not obscured by derm) closely 
punctate, the punctures larger on epistoma and labrum. Antennae 
not extending to base of prothorax, third joint as long as fourth 
and fifth combined, 4-7 increasingly wider, obconic, 8-10 shorter 
and narrower than seventh, eleventh sharply acuminate, little 
longer and narrower than the tenth. Prothorax 6 x 10.5 
mm., widely emarginate at apex, wider at base than at apex, 
widest at middle, anterior angles rounded and obtuse, sides widely 
rounded, a little sinuate near base, posterior angles shortly pro- 
duced backwards and acute, base truncate, margins regular, wide 
and explanate with extreme edge very narrowly raised, whole pro- 
thorax without perceptibly differentiated border and (where not 
obscured by derm) strongly but not closely punctate ; disc very 
convex, without fovea? or canaliculation. Scutellum widely trian- 
gular. Elytra 14 x 12 mm., shoulders; rounded but emphasized by 
epipleural fold, convex longitudinally and transversely, highest 
and widest behind middle, gradually widening from shoulders to 
near apex, with very narrow horizontal border (evident from above 
throughout, suture flat, a row of large lateral punctures, clothed, 
but not punctate, like head and prothorax (an abraded specimen 
