994 



Moreover this pattern occurs almost completely on the hind-wing 

 as well as on the front one. For also there the first row forms a 

 convex dark blotch occupying five internervural cells along the 

 outer margin, with three darker centres next to corresponding 

 veins. In the same way the transverse bar II is composed of dark 

 spots, curved outward and is accompanied on botli sides by a less 

 dark bar of more diluted spots. The number of compouents of bar II 

 is smaller than on the fore-wing, the hindei' three being concealed 

 undei' the covering of red hairs. The fourth and fifth spot (counting 

 from the front border) are straighter than tiie rest, and placed 

 somewhat more inward, while they show rather a darker hue. 



Row III and IV stand in contact with the corresponding ones of 

 the fore-wing, but disappear under the red covering even sooner 

 than II. V and VI are only indicated by dark spots along the front 

 margin, these spots moreover for the greater part being concealed 

 under the overlapping fore- wing. 



VII is totally invisible. 



On the under side of the wings the pattern perfectly corresponds 

 with that on the upper side, but on the fore-wing it is paler and 

 partly indistinct, on the hind-wing on the contrary it is sharper and 

 more complete than on the iijtper surface, because the red hairy 

 covering is absent on the former. The front-rim of the hind-wing, 

 remaining uncovered on this side, sharply contrasts both by colour 

 and pattern with the rest of the wing-surface and wears one espe- 

 cially dark spot, forming the initial component of Bar IV. It seems 

 desirable to indicate this peculiar spot by a special name, as it was 

 also done with those of the fore-wing: viz. the hind-wing-frontborder- 

 spot. In a single of the specimens at my disposal I also found the 

 markings along the front-border of the under side of the fore-wing 

 differentiated and specially spotted. 



On the under side of the hind-wing Bar V and VI are not repre- 

 sented, either by their initial (fiontal) elements or by other spots of 

 their row, neither can Bar VII be distinguished ; the light discoïdal 

 marking however being well visible, as it strongly stands out against 

 the broad anterior part of Bar IV. 



Now let us compare this pattern of the Poplar Hawkmoth with 

 that of the Eyed Hawkmoth. The close kinship of Sm. ocellaia 

 with popidi appears from several points of cori-espondence, but 

 surely most convincingly from the possibility of crossing these two 

 species together, the reciprocal hybridisation leading to different 

 results and the hybrids themselves being again fit for propagation. 

 On these accounts the classing of these two species into two different 



