252 E. II. Sellards — Types of Permian Insects. 



a curved course and reaches the inner border well toward the 

 apex, and has, as is usual with the general run of Odonata, 



2 



Figure 2. — Base of the right front wing of Tupus permianus. 0, costa ; 

 Sc, subcosta ; K, radius ; Mj.3, branches 1 to 3 of media ; M 4 , fourth branch 

 of media ; Cu, cubitus ; A, anal. Drawn with the camera lucida ; enlarged 

 four diameters. 



particularly Odonata Anisoptera, a considerable number of 

 veins from the lower side filling the space between itself and 

 the cubitus. M 3 separates from M,_ 2 , and, again agreeing to 

 a surprising degree with M 3 of Anisoptera, runs in' a curved 



course parallel and close to M 4 . 

 No interpolated veins appear 

 between M 3 and M 4 . M x _ 2 di- 

 vides opposite the subnodus ; 

 from this point both divisions 

 continue as simple veins, pre- 

 senting again an unexpected 

 agreement with Odonata Ani- 

 .soptera. 



Radial sector, subnodus, and 

 oblique vein. — It is a well- 

 Figiire 3.— Base of the wing of a known fact that to recognize 

 modern dragon-fly. Lettering and the radial sector in the adult 

 enlargement as in figure 2. Both dragon-fly wing is often a mat- 

 wmgs are viewed from the ventral J => ,. ,. aL ,, » T1T . n £l 1 

 surface, the body obscuring the ex- ter ot difficulty. With the J^al- 

 treme base of the wing. eozoic forms, the adults only of 



which are available, we must 

 therefore expect to recognize the radial sector, as a rule, from 

 its relation to other veins rather than from any evidence in 

 the sector itself. Fortunately, however, in most dragon-flies 

 structural evidence bearing on the position of the radius is not 



wanting even in the adults. 



The keen observations of Need- 



