992 



lighter part two small dark spots toucliing the front-rim of the wing 

 may again be distinguished, each of them composed of two trans- 

 verse striae. In some specimens of Smerinthus populi the proximal 

 border-rim of the central area is also clearly double. Next to the 

 wing-root in the lightgrey hue of this part, a faint indication of a 

 dark ribbon may be detected besides. 



Of the various hitherto mentioned bars of dark spots, the outer- 

 most, which is by far the strongest and completest, consisting of 

 nine separate elements when accurately counted, takes a sinuous 

 course. Counting from the front backwards, the tifth spot is situated 

 furthest inward, it also is the shortest and straightest. In many 

 specimens this spot is obviously darker in hue than the rest, and 

 this difference deserves our attention, as it is met again in allied 

 species, but here increased in intensity and extension. 



On the inner and (tn the outer side of the just mentioned rows 

 of spots there occurs a broader bar of less obscure and tnore faintly 

 circumscribed markings, which however are evidently darker than 

 the grey shade of the lightest wing-areas, playing the role of ground- 

 colour. The outer of these two collateral bars is separated from the 

 median series by a iiarrow sharply traced light interval. From the 

 internal bar it differs by lesser regularity, some of its components 

 being broader than the rest, and at the same time darkei'. This is 

 especially the case with the spot near the hindborder of the wing, 

 this spot broadening obliquely in an outward and posterior direction, 

 and thereby just touching the hinder angle of the wing. A similar 

 triangular broadening also occurs at the front end of the bar, near 

 the apex of the wing, but here it has a lighter hue. 1 think it 

 desirable to indicate these spots by special names, e.g. anterior and 

 posterior triangular spot, as they are found again with increased 

 clearness and independence in allied speckles 



In the middle j)art of the bar under discussion four of the spots 

 clearly show the hourglass- type. In front of them the bar coalesces 

 with a dark area, extending along the greater part of the outer 

 margin of the fore-wing. This area forms a large convex blotch, 

 occupying five internervural cells from the apex backward. 



Though at first sight this blotch is not divided into separate spots, 

 yet three darker centres may be distinguished in it, touching the 

 foreside of the nervures which take their course through it. A 

 comparison with other species of the same genus and of different 

 allied genera again proves, that these darker centres may be con- 

 sidered as originally independent separate spots — one in each 

 internervural cell— which have coalesced with each other into a single 



