THE WINGS OF MECOPTERA 303 



elusions, as the venation of the wings is so nearly typical that the identifica- 

 tion of the veins presents no difficulties. 



In some cases, as in the fore wings of certain species of Panorpa, the 

 number and the arrangement of the wing-veins is that of the hypothetical 

 primitive type, with the 

 addition of a considerable 

 number of cross-veins; 

 and in all cases, except- 

 ing the aberrant genera 

 Merope and Notiothamna, 

 the modifications of this 

 type are comparatively 

 slight. 



The most obvious 



modification of the prim- ^. ^ c u- a ■ ^t -d^.,^,^^ 



^ Fig, 315. — Base of a hind wing of i^OMorpa. 



itive type is the presence 



of one or two accessor}^ veins on one or more of the branches of the 



radius. These are borne most frequently by vein Ro. 



Another modification of the primitive type that exists commonly is the 

 anastomosing of one or of both branches of the cubitus with the adjacent 

 vein ; that is vein Cui anastomoses with vein M, and vein Cuo with the first 

 anal vein. In the fore wing of Panorpa (Fig. 314) each of the principal 

 veins extends separately from the base of the wing; but in the hind wing 

 each of the branches of the cubitus anastomoses with the adjacent vein. 

 This is shown more clearly in the enlarged figure of the base of the hind 

 wing (Fig. 315). 



The relation of the branches of the cubitus to the adjacent veins in the 

 three common winged genera was pointed out by Miyake ('13). In the 

 fore wings of Panorpa and of Panorpodes the principal veins extend separ- 

 ately from the base of the wing. In the fore wing of Bittacus, veins Cui 

 and M anastomose, but vein Cu2 is separate from the first anal vein. In 

 the hind wings of all of these genera, each of the branches of the cubitus 

 anastomoses with the adjacent vein. 



(c) THE ABERRANT MECOPTERA 



There are two genera of insects which, although they differ greatly in 

 appearance from the typical members of the Mecoptera, are doubtless 

 members of this order. These are Merope and Notiothaurna. 



The genus Merope is represented by a single species, Merope tuber which 

 was described by Newman in 1828 (Ent. Mag. V. p. 180). Newnnan was 

 unable to decide as to the zoological position of the genus. Later West- 

 wood ('41), from a study of the mouth parts decided that it should be 

 placed in the Panorpida;. 



