216 THE CANADIAN ENTOMOLOGIST. 



some papers on fossil insects, I have used my own, and have given, Stett. 

 Ent. Zeit., 1870, a more general paper on the rational nomenclature of 

 the venation in the wings of insects. The plate accompan)ang this paper 

 was made at my request by my old friend, Zeller, as I was then on a long 

 voyage. The numbers and the f at veins on the plates are all Prof Zel- 

 ler's, and very different from my views. As the plate had been published 

 before my return, it has not been given any explanation, because the plate 

 did not illustrate my views. 



I may add that I have studied carefully Dr. Adolf's recent papers on 

 veins of insect wings, in the hope of finding a better explanation for the 

 aborted or undeveloped veins, but without success. The costa runs as a 

 true and strong vein along the anterior margin to the middle of the rounded 

 apex of the wing, where it is commonly connected with the submediana. 

 The costa is incised at its extreme base ; the very small part before this 

 incision, which lies not exactly in the same line with the costa, is, together 

 with the very minute part below it, homologous with the basal squama. 

 The sub-costa is the strongest and darkest vein, straight, ending free in the 

 basal third of the length of the wing, somewhat earlier in the hind wings. 

 I am not able to confirm (even from wings in alcohol) Wood-Mason's 

 statement that it would, if produced far enough, run into the costal vein. 

 Sometimes it seems indeed more directed to the costa, but in other species 

 (0. IVestwoodi) it seems to run to the sinus of the mediana. 



Out of the mediana (radius) originates at its base below the subcosta, 

 and a little before it above the costa ; the mediana runs as a very large 

 and diaphan vein (the subcosta is not diaphan) parallel to the costa to 

 the apex of the wing. Shortly before the apex the mediana is bent down 

 and united in a curve with the submediana. Out of the middle of this 

 curve runs a straight, short vein to the apex, which as I believe belongs to 

 the submediana. An abnormal specimen of 0. atricapilla and both 

 specimens of 0. IVestwoodi do not possess this curve in all the wings ; the 

 mediana is connected by a straight transversal with the submediana, and 

 ends shortly after this transversal obliquely in the costa. The mediana 

 runs in the middle of a large sinus, " studded thickly on each side with 

 microscopically minute setae " (Wood-Mason), or between two sinuses 

 following its whole length. I can not decide which view is better to be 

 accepted, but I remark that a somewhat analogous sinus is to be found in 

 a part of the wings of Psocina. I have remarked before that the four 

 dark parallel lines described and figured for this place are formed of the 



