402 Records of the Indian Museum. [Vol. XXIV, 



Abdomen black, marked with yellow as follows : — Sides of first 

 and second segments, including the oreillet ; dorsum of first seg- 

 ment, and a longitudinal band on dorsum of second segment, the 

 latter mark narrowing apically ; a basal ring, occupying nearly 

 the first third of segment three, but contracted dorsally in the 

 middle line, in addition a distal lateral yellow mark ; a similar basal 

 ring on segments 4-7, but relatively smaller, and occupying only 

 about one-quarter of each segment. Eighth segment entirely black, 

 ninth with a dorsal triangle of orange-yellow, its base resting on 

 the apical margin of the segment, its apex not quite touching the 

 base of the segment. Terminal segment black. 



Anal appendages black, very similar to those of B. pyramidalis. 

 The upper pair about as long as segment 10, acuminate, very 

 slightly upturned at the apex, elbowed on the outer margin. Lower 

 appendage a shade longer, its branches rather more divaricated 

 than are the upper appendages, upturned at the apices. 



Genital structures of second segment of abdomen similar to 

 those of B. pyramidalis , but the first pair of hamules are relatively 

 larger and more prominent, the second pair not so oval but sloping 

 obliquely backwards and ending in a forwardly directed hook. 



Length of abdomen of q»33+i mm., of hinder-wing 25*5 mm. 



Group Onychogomphus. 



Fore-wing and hinder-wing showing equal specialization in 

 regard to the cross-nerves between M t _ 3 and M + . Sectors of 

 arculus as in preceding tribe. Cu t and Cu 2 nearly parallel as far as 

 wing margin. Pterostigma braced. M 4 and Cu, parallel to level of 

 nodus in fore-wing. A 2 separated from A, by two rows of cells 

 from immediately below the subtriangle, whereas in the preceding 

 tribe there is usually a single cell between them at their origin ; 

 further A 2 lies nearer the wing base in this tribe than in Gomphus. 

 Legs very short, hindermost femora scarcely reaching beyond the 

 end of the synthorax when adpressed. Colour pattern not afford- 

 ing any definite characters for separation of the tribe. Upper 

 anal appendages of male longer than tenth segment of abdomen, 

 often equal in length to the ninth and tenth segments together ; 

 parallel or converging apically, arcuate. 



Genus Onychogomphus. 



Genotype ; 0. forcipatus (Linn.). 



Species examined : [0. forcipatus (Linn.)] ; 0. lineatus 



Selys; 0. grammicus, Selys ; 0, saundersi Selys ; 0. 



aureus, sp. nov. ; 0. M-flavum Selys ; 0. biforceps Selys ; 



0. acinaces, sp. nov. 



Characters of the tribe. 



Distribution: Warmer parts of Europe, Africa, tropical Asia 

 as far as the Celebes. 



I group the species of this large and rather difficult genus in 



