1900.1 Catalogue of the Coleoptem of South Africa. 119 



about one-thii'cl of the size ; prothorax convex ov dehiscent iji the 

 anterior part, depressed or sometimes plane behind, carinate in the 

 anterioi" and lateral part, and often along the base the central part 

 of which is projecting and bears two more or less deep or oblique 

 impressions, and the lateral fovea is very conspicuous ; the scutelhmi 

 is hardly visible ; elytra more or less sinuate laterally, plaiu; or 

 moderately convex, as bi'oad as the base of the prothorax, they have 

 nine stritc, the ninth interval is produced in a sharp carina close 

 to the eighth stria, and there is a conspicuous humeral diagonal 

 callus on the seventh, eighth, and ninth intervals, the epipleura are 

 distinct; pygidium triangular, slightly convex; prosternum without 

 intercoxal process except in 0. castelnaui and 0. audens, meso- 

 sternum invisible ; metasternum wdde, sometimes deeply grooved, 

 and having always two impressions at the base ; abdomen short ; 

 anterior legs longer in the male than in the female, the fore tibiae 

 are quadri-dentate outwardly, more or less curved or falcate at apex in 

 the male with the apical part curved and mucronate and without any 

 apical inner spur; this spur is, however, found in the female the 

 anterior tibiae of which are quadri-dentate outwardly and normal ; the 

 anterior tarsi are wanting in both sexes ; the femora and the tibiye 

 of the male are armed with spines or crenulate laminae usually 

 wanting in the female, the intermediate and posterior tibiae are 

 broadly dilated and triangular at apex. 



The sexual differences of the insects included in this genus are very 

 great. In the female not only does the shape of the clypeus vary, 

 but often the clypeal carina varies also, and, as a rule, whenever 

 there is a tubercle, this tubercle, as well as the vertical margin, are 

 more raised; in 0. Castelnaui the vertex bears even a conspicuously 

 cristate process. The genus is represented in Southern Europe, and 

 the circa-Mediterranean region ; Africa (Senegal, Egypt, Abyssinia, 

 Galla, Somaliland, Sierra Leone, Old Calabar, Congo, Victoria 

 Nyanza, Albert Nyanza, Nyassaland) and Asia (British India, 

 Burmah, Indo-China, Siam, Ceylon, Java, Sumatra, The Philipine 

 Islands, New Guinea). 



Keij to the Species. 



A-. Head with a clypeal and a frontal carina. 

 B-*. Not interrupted. 



C^. JMucro of anterior tibia? of <? sharp and long. 

 D=. Prosternum of c? produced in a bifid process. 



Anterior femora with a very long, arcuate tubercle at 

 the lower edge ; prostevnal process pedunculate with the 

 bifid part horizontal castelnaui. 



