220 



THE WINGS OF EPHEMERIDA 



of perfection that has been reached in the alternation of convex and concave 

 veins. In the accompanying table the names of the convex veins, those 



Fig. 221. — Wing of a nymph of Siphlurus (After Morgan). 



veins that follow the crests of ridges, are printed in boldface type; while 

 the names of concave veins, those that follow the furrows, are printed in 

 ordinary Roman type. 



TABLE OF THE WING-VEINS OF THE EPHEMERIDA 



The convex veins are indicated by boldface type 



BASE OF WING 



Costa 



Subcosta 

 Radius 



Media 1+2 



Media s+4 



Cubitus 



1st Anal Vein 



2d Anal Vein 

 3d Anal Vein 



DISTAL PART OF WING 



Costa 



Subcosta 

 Radius 

 Media one 

 Intercalary vein Mi 

 { Radial sector 

 Intercalary vein Rg 

 Media two 

 Media three 

 Intercalary vein Ms 

 Media four 

 Cubitus one 

 Intercalary vein Cui 

 Cubitus two 

 1st Anal vein 

 2d Anal vein 

 3d Anal vein 



ABBREVIATIONS 



c 



So 



R 



Ml 



IMi 



Rs 



IRs 



Ma 



Ms 



IMs 



M4 



Cui 



ICui 



CU2 



1st A 



2d A 



3d A 



It will be seen by reference to the tabic that the alternation of convex 

 and concave veins exists in all parts of the wing. In the basal portion of the 

 wing convex and concave principal veins alternate except in the case of 



