BY R. J. TILI.YARD. 603 



13 mm. from the base, whereas the total length is 31 mm., 

 which seems to me rather too much for the "little, less," 

 though that is only a personal opinion. 



Further points of great importance, which differentiate 

 this genus from Devadatta and all other Calojyterygme genera, 

 and shew it to be a close approximation to Lestes, are the 

 absolute elimination of all cross-nervures in (a) the post- 

 costal space above the petiolate anal vein, and (b) the whole 

 space lying below R, from the arculus to the nodus. [In this 

 connection it is also interesting to note that the position of 

 the oblique vein is very variable in this genus. It is usually 

 the fliird cross-vein from the join of Mj with M3 (see figure), 

 but is not infrequently the fifth, and sometimes the fourth.] 

 This line of specialisation, if continued until all but the first 

 two antenodals were eliminated, the quadrilateral depressed 

 and narrowed, and the distance between the arculus and 

 nodus considerably lessened, would give us a close approach 

 to a true Lestine wing. 



The generic characters, amended on the above lines, will 

 now be as follows — Two antenodals only, viz., the one before 

 and the one above the arculus, continued into the subcostal 

 space. Quadrilateral, basilar space, postcostal space as far 

 as the petiolation of the wing, and the whole of the space 

 below the radius from the arculus to the nodus, free. Nodus 

 lying at a distance less than one-half but greater than one- 

 third of the whole wing-length, from the wing-base. M„ 

 departing from ^^■^ under or very close to the nodus. M^ and 

 Cui diverging from one another slightly as they proceed to 

 the wing-margin : a single row of cells at first between them, 

 increasing to three or more rows, with or without distinct 

 sectors. Superior appendages of male forcipate. Colour of 

 male bright blue, with more or less black markings. Wings 

 either clear or more or less barred or shaded. 



Type, Diphlebia lesto'ides, Selys. 



