OllEODEEUS. 223 



6 (3) Pronotum not distinctly cariuate. 



7 (8) Terminal spiracles not prominent : 



body not tufted Idiovalgus, p. 230, 



8 (7) Terminal spiracles prominent : pro- 



notum and pi-opygidium tufted. . . . Xexoreoderus, p. 232. 



9(2) Front tibia armed with five teeth .. Dasyvalgus, p. 233. 

 10 (1) Pygidium flat, about as long as it is 



broad : $ with caudal appendage . . Charitovalgus, p. 246. 



Genus OREODERUS. 



Oreoderus, Burm., Handb. Ent, iii. 1842, p. 726; Kolbe, Stettin. 

 Ent. Zeit. 1904, p. 25. 



Type, Valgus argillaceus, Hope. 



Range. ludia, Burma, Siam, and the Malayan Kegion. 



Body of variable shape, but frequently long and narrow, clothed 

 with short flat scales, the legs not long, the front tibia armed 

 with three very strong teeth occupying the whole outer edge, the 

 first joint of the hind tarsus shorter than the succeeding one. 

 Clypeus moderately long, contracted in front of the eyes, broadly 

 rounded in front, with the angles detlexed, sometimes sharp but 

 not conspicuous. First joint of the antenna large, produced beyond 

 the point of articulation of the second joint. Prothorax rather 

 narrow, the episterna produced freely forward and forming witli 

 the front coxsd a deep cavity for the reception of the head. 

 Pronotum bearing two strong ridges, prominent and generally 

 united in front. The propygidium and pygidium are broad and 

 exposed, the terminal spiracles scarcely elevated, except in 

 0. momeitensis. The fifth ventral segment is twice the length of 

 the anterior segments. 



The sexual differences are various and often very great. Usually 

 the female is relatively narrower than the male, but in 0. gravis 

 it is broader. The propygidium is frequently horizontal and more 

 or less produced in the female and there is sometimes a colour 

 difference. The hind tarsi of the male are longer. 



Keg to the Species. 



1 (2) Pronotum bearing two hooked tubercles [p. 224. 



in front argillaceus, Hope, 



2 (1) Pronotum bearing a rounded lobe in 



front. _ [p. 224. 



3 (4) Terminal spiracles sharply elevated . . momeitensis, sp. n., 



4 (3) Terminal spiracles scarcely elevated. 



o (10) Thoracic carinas not continued back- 

 wards beyond the middle. 

 6(9) Bodylong; elytra not tuberculate behind. [p. 225. 



7 (8) Posterior angles of thorax very blunt. . hhutanus, sp, n., 



8 (7) Posterior angles of thorax sharp rzifulus, Gestro, p. 225. 



9 (6) Body short ; elytra tuberculate behind . brevipennis, Gestro, 



10 (5) Thoracic carinfe extending backwards [p. 226. 



beyond the middle. 



11 (16) Elytra not tuberculate behind. 



