Mr. W. li. Distant on Ilomoptera. 69 



wicltli of the tegmina is scarcely more than a third of tlieir 

 length ; opercuhi ochraceous, narrowly margined with black 

 and obh'quely black at base, in shape and length resembling 

 those of JJ. imperatorid. Allied to /*. merula by the relative 

 breadth and length of tegmina, and by having the third 

 apical area to the same shorter than the fourth, but differing 

 by the shape and length of the opercula. 



Long., excl. tegm., (^ 64 mm,; exp. tegm. 176 mm. 



Ilah. Tenasserim : Thaungyang Valley [Col. Bingham, 

 Brit. Mus.). 



The structural differences of the three species are expressed 

 in the following synopsis : — 



A. Opercula about as long as broad, 



a. (Jreatest width of tegmina much more than a third 

 of their length. 

 b. Third apical area to tegmina about as long as 



fourth P, imperatoria. 



aa. Greatest width of tegmina about or little more 

 than a third of their length. 

 bb. Third apical area to tegmina shorter than fourth. P. intermedia. 



B, Opercula broader than long P. merula. 



DoKUMA, gen. nov. 



Head (including eyes) as wide as base of mesonotum, its 

 length about equal to breadth between eyes ; pronotum con- 

 siderably shorter than mesonotum, its lateral margin distinctly 

 angularly toothed; mesonotum with a transverse tumidity at 

 and extending beyond the cruciform elevation ; abdomen in 

 male considerably longer than space between apex of head 

 and base of cruciform elevation ; tympana very large, a little 

 convex, nearly meeting inwardly, and between them the 

 prolonged metanotum appears as a longitudinal subconical 

 process ; opercula small, between their inner margins a short 

 subglobose metasternal process ; rostrum reaching the posterior 

 coxce ; tegmina and wings hyaline ; tegmina with eight 

 apical areas, the basal cell longer than broad. 



Type, D. nigristigma,y^a\k. [Dundabia), 



AOLA, gen. nov. 



Head (including eyes) about as wide as base of mesonotum, 

 its length about equal to breadth between eyes ; front pro- 

 minent, its lateral margins more or less continuous with those 

 of vertex; pronotum distinctly shorter than mesonotum, its 

 lateral margins prominently toothed ; abdomen short, about 

 as long as space between apex of front and base of cruciform 

 elevation; tympana entirely covered, the flaps broader than 



