Tllfe CANADIAN ENT'OMOLOCilST. 201 



NOTE ON THE DIURNALS. 



BY A. RADCLIFKE GROTE, A. M., ROEMER MUSEUM, HILDESHEIM. 



Mancipium brassicce. — Dr. Chapman writes me tliat certain speci- 

 mens of this common species examined by him showed the very short 

 veinlet III. 3 + 4. This veinlet constantly diminishes in size, progressing 

 towards the tip of the wing to finally vanish, through many forms of 

 the Picridce. I had indeed expected it to be occasionally persistent 

 in brassicce^ although my preparations did not show it. It has disap- 

 peared in Pontia daplidice, in Nathalis io/e, and, strange to say, in that 

 curious and now isolated Pierid, Gonophlebia paradoxa. This varia- 

 bility, in one and the same species, is interesting because it follows the 

 general evolutionary direction of the changes in the venation. Always 

 the radial branches in the Pierids and other groups tend to diminish in 

 number. Always the disintegration of the Media advances, until it 

 finally disappears, as a system, from the surface of the wing {Rotkschi/dia, 

 Samia, Potatnis, etc.). A parallel case to that of brassicce. is offered by 

 Copismerinthus ocellata. In some specimens of this Hawk Moth, vein 

 IV, is still thrown off from the cross vein of the hind wings, instead of 

 the Radius, which it has usually ascended to beyond the cell. We must 

 regard these as instances of generalization in the individual, of a reversion 

 to what was formerly the rule and is now becoming, by slow degrees, the 

 exception. Mr. Scudder kindly informed me that lie believed that slight 

 structural differences in all stages of brassicce could be demonstrated as 

 compared with the type of Pieris. In my studies I am mainly concerned 

 with the correct use of generic names extant in literature, without 

 attempting to judge of the comparative value of such differences ; if any 

 characters can be found I take them as generic if a title exists in litera- 

 ture. We may reasonably regard Mancipium as a development of Pieris 

 since it shows a further progress upon the same structural lines. I have 

 tried to show that Pontia presents a parallel advance, but upon a distinct 

 phylogenetic terminal line, belonging to the Ant/ioc/iarini and not to 

 Pieris as heretofore classified. The five-branched Radius of Euchloe 

 Stella has been reduced to four in TetracJiaris cethura, to three in Pontia 

 daplidice, which retains the x\nthocharid pattern and shape of wing. 



Eiiviargareta coresia. — -I have recently studied this South American 

 Nymphalid, which belongs taxonomically to the Nymphalince, but differs 

 by position of the last radial branches, and can hardly be a member of 

 the phylogenetic group to which Limenitis and Nymphalis lucilla 



