188 THE entomologist's KECORb. 



longitudinal streak. The oblique costal streak (No. 8 above) is 

 exceedingly variable, being usually broad and well-developed, and 

 giving out from its centre two branches, one on each side, at right 

 angles to the line of its direction, one joining the longitudinal streak 

 at some distance before its termination, the other joining the lower 

 end of the apical streak ; occasionally, however, it is narrow and 

 unbranched, or only branched on one side ; when this is so, it is 

 usually the inner branch (the one that joins the longitudinal streak) 

 that fails first. The apical streak is usually lunular in shape, varies 

 much in width, and is, more often than not, joined at its base to 

 the oblique costal streak, as previously described. It frequently also, 

 on its outer edge, gives off tiny pointed serrations, which occasionally 

 reach the outer margin ; very rarely it becomes so broad as to absorb 

 the normally black apex of the wing. On the other hand, it is some- 

 times very much reduced, and then arrives at the normal condition of 

 the American /irtrasa, the absence of this apical marking being very 

 frequent in the latter form (or species). The longitudinal streak 

 varies much in width, being broadest towards the base, and narrow- 

 ing at about the centre of the wing ; occasionally it is divided at this 

 point into two distinct portions. We have before observed that it is 

 frequently united by a branch line with the oblique costal streak 

 (No. 3 above), and the lower side of the longitudinal streak often 

 iDears a prolongation as if the branch portion had cut right through 

 it and had been continued on the outer side, and it is actually thus 

 continued in a few of my specimens until it reaches the inner margin. 

 The longitudinal streak usually ends before it reaches the anal angle ; 

 sometimes it bifurcates at its extremity, giving oft' two fine branches, 

 one joining the base of the oblique line, the other running out to the 

 margin at the anal angle. 



The females are probably more uniform in the distribution of the 

 black and cream colours of the fore-wings than the males. Compared 

 with the latter, the costal basal streak is usually, perhaps, a little 

 better developed, and the longitudinal streak often becomes Avider, 

 more often united with the pale costal streaks, and more branching at 

 the anal angle. I have a female bred from larvae, sent to me from 

 Winchester, by the Rev. G. M. A. Hewett, in 1893, a male bred by 

 the same gentleman in 1890, and another male bred by Miss lumber, 

 in which the cream colour greatly preponderates, and the black area 

 is, of course, proportionately curtailed. 



Whilst I have been examining my specimens for the above facts, 

 my attention has been riveted upon a detail which appears to me to be 

 of remarkable significance. It is, that X plaiitat/ini.s exhibits in 

 its hind-wings an arrangement of the black and yellow markings 

 perfectly parallel with that exhibited by the fore-wdngs. In fact, the 

 modifications are so simple that one cannot fail to trace the peculiarity 

 as soon as it is pointed out. Evidently, then, the markings of the 

 fore- and hind-wings were at one time probably identical. It is 

 necessary to get a long and variable series of specimens to work this 

 similarity out in detail, but when such examination is made, there 

 can be no doubt of the fact. 



The black markings of the fore-wings may be said to consist of 

 three oblique costal marks, and these have exactly analogous markings 

 in the basal costal mark, the discoidal lunule and the upper spot 



