1331. 



DRA a ON-FL Y WING VENA TION—NEEDHA M. 



733 



iterial to be had for tracing- genealogies, and we will attempt to 

 pint out only the niore important venational features, comparing 

 tern with the conditions we l)elieve to be primitive for the order. 



{ /Jorogoviphus.^Thh {^g. 24) is an isolated living type, specialized 

 i the extensive differentiation between fore and hind wing by the 

 cvelopment of an exi)anded anal area upon the latter, generalized in 

 V unbraced stigma and in its retention of cross veins in the space 

 I'fore the arculus. It parallels Macromia vioorel in the peculiar form 

 (■ its anal loop, and IIrm!(inax ephippiger (Plate XXX VJ, lig. 3) in 

 re circuitous course of vein C>i.,. It is unique among the Odonata 



lown to me in that the triangle of the hind wing has been elongated 



ansversely to the axis of the wdng, while that of the fore wing is 

 ijuilateral. 



Flc. 24.— WlNiiS <iF C!il()yoriniiii)liii.<! ma(inifirii!< Hki.YS. FEMALE. 



ne Cordidegaster gnnip.^'nu^ small group has retained some decid- 

 ■dly primitive features. Anal vein and second cubito-anal cross vein 

 ,iave retained their primitive position and relations in both wmgs. 

 The triangles are alike, and only moderately elongated. No supple- 

 nents are developed; and there is no brace to the stigma, or only a 

 L-ery imperfect one in I^ialla and its allies. There is, however, a mod- 

 n-ate enlargement of the base of the hind wing, and this becomes 

 uioulate in the males. Corded eg mter say! (tig. 25) and PhijUopetaUa 

 'ipkidU (Hg. 20) represent the divergence of the group; there is uni- 

 iformity in the more important wing characters. There has been a 

 idight development of accessory branches upon the radial sector, and 

 iin the wing of Ph)/U<>petal!a will be noticed the undulate course taken 

 3n by veins J/, and Rs, and by ^f., and J/,; but the reduction of redun- 



