154 ANNALS OF THE QUEENSLAND MUSEUM. 
and tarsi red. Head — Labrum prominent, epistoma squarely trun- 
cate in front, joining- the can thus at a wide angle, a little concave 
and depressed below the level of the forehead but without any 
separating' suture, forehead with deep transverse fovea, whole head 
minutely punctate ; antennae third joint as long as fourth and fifth 
together, joints -1-7 obconic, 8-10 transverse and subtriangular, 
eleventh longer than tenth, ovate -acuminate. Prothorax 4x8 
mm. (length in the middle), greatest width behind the middle, 
wider at base than apex, anterior angles acutely produced in front 
of eyes, the angle only narrowly margined at apex, sides widely 
rounded, strongly sinuate! before the acute posterior angles, the 
latter dentate and slightly twisted outwards ; lateral border strongly 
thickened, rounded and raised, rather widely channelled within 
throughout, basal border very narrow, disc apparently quite 
smooth. Scutellum widely transverse and raised. Elytra 11 x 10 
mm., of same width as prothorax at base, widely oval, very convex, 
greatest width behind middle, apical declivity steep, each elytron 
separately rounded at apex, shoulders obsolete, border very 
narrow, channel within scarcely perceptible, disc very smooth, 
without a trace of definite sculpture, sutural region depressed behind 
scutellum, and showing faint transverse impressions. Abdomen 
faintly striolate on basal segments, and faintly and minutely punc- 
tate on the apical ; all coxae punctate and margined by carina, 
prosternum impressed with a. single transverse line, its, process pro- 
duced into a blunt tooth, without any pustule on its front margin, 
submentum coarsely punctate, its lateral teeth small and blunt, 
mentum cordate, maxillary palpi with apical joint triangular. 
Dimensions: 17x10 mm. 
Habitat: Kookynie, West Australia. 
A single specimen, male ( ?), sent by Mr. Edgar Duboulay, 
after whom I have much pleasure in naming it. There is a very 
faint line of hairs on the inside of the hind femora. This species 
could only be confused with 0. major, Blackb., and 0. heta, Bl., 
from both of which it differs by its strongly thickened border of 
prothorax, while it is much smaller than major, Bl. It is much 
larger than, with quite a differently shaped prothorax to, 0. 
lugubris, Bl. 
