BY R. J. TILLYARD. 191 



this line of descent was like, and also try to discover whether 

 any other Zygoptera exhibit a bridge-vein. 



Now in the very remarkable dragonfly, Epiophlehia superstes 

 Selys, whose wings are figured by Needham {loc. cit., Plate xli., 

 fig. 3), a typically Lestine bridge, with clearly indicated oblique 

 vein, can easily be made out; and will, I feel sure, readily be 

 recognised and accepted by all students of Odonata without 

 requiring corroborative evidence from the larval wing, which 

 will probably never be found, even if the dragonfly be not already 

 extinct. The remarkable and isolated wing-type shown by Epio- 

 phlehia has so many points of Lestine affinity, that it may well 

 be claimed to lie on the direct line of descent of that genus. The 

 chief difference lies in the much greater reduction of the Lestine 

 wing, and the departure of M2 from M^ far distad from the sub- 

 nodus. The latter is, however, a characteristic of all highly 

 reduced Zyyopterid wings, and must be considered as a specialisa- 

 tion brought about by the shifting of the nodus basad. The 

 trachea M., need not follow the subnodus towards the base, since 

 it is not really connected in any way whatever with either Sc or 

 R, and its function is to supply the middle portion of the apical 

 part of the developing wing. The genus Archilestes shows an 

 intermediate position of Mg. 



In quite another direction, Epiophlehia shows strong relation- 

 ship to the Anisoptera, particularly to the Gomphince. In the 

 larger Gomphince, the oblique vein is placed about as far distad 

 from the subnodus as it is in Epiophlehia, and the bridge itself 

 is almost, if not quite, as long. Furthermore, in both, M., de 

 scends from the subnodus, and there are two thickened anasto- 

 mosing antenodals of flat triangular form. Finally, apart from 

 its wing-venation, Epiophlehia is characteristically Gomphine in 

 the short build of its body-parts, in the large size and closeness 

 af the eyes in the male, and its archaic bicolorous {hylochrome) 

 colour-pattern. 



We stand here, in fact, almost on the verge of the first dicho- 

 tomy between Anisopterid and Zygopterid forms. It needs but 

 a single cross-vein inserted into the quadrilateral of thehindwing 

 oi Epiophlehia to turn that cell into a weak " supertriangle -f- 



