NEW ABERRATION OF ZONOSOMA LINEARIA. 6 



in common in their general "make-up," illustrating in varying 

 degree the potentialities of ** concentration " of the dark colour 

 into costal blotch or blotches, of which I spoke in discussing 

 Mr. Nurse's and Mr. Webb's aberrations. As this phase of 

 variation now proves to be recurrent, and not entirely confined 

 to asymmetrical manifestation, I think it convenient to give it a 

 special name, ab. costimacula, nov. ab., and designate Fig. 5 the 

 type thereof. Those who believe in naming every differentiable 

 form may like to add names for Figs. 2 and 3, but I prefer to 

 cover by the name all forms which have a dark blotch in the middle 

 of the costa followed by a suffusion of white in the middle of the 

 wing. The distinctions between the three specimens in question 

 are well shown in the figures : No. 2, with its very extended pale 

 area and the blurred inner marginal markings, is the most ex- 

 traordinary ; Fig. 5 is on the right wing intermediate between 

 costimacula and ovulata. 



As regards Fig. 6, it is the only example yet known in which 

 the ground-colour, as well as the scheme of markings, has 

 materially changed. The parts which are ordinarily brown (and 

 which, in spite of their reduction, I still regard as theoretically 

 the " ground-colour ") are ochreous, only a shade darker than 

 in Perizoma flavofasciata (decolorata) , while the white parts are 

 duller white than is typical. The general scheme somewhat 

 suggests a nebulous ab. costimacula, vaguely akin to that in 

 Fig. 5. N 



A NEW ABERRATION OF ZONOSOMA LINEARIA. 



By Louis B. Prout, F.E.S. 



The very interesting aberration of Zonosoma linearia figured 

 (Plate I., fig. A) was taken by my friend, Mr. D. P. Betts, in 

 Epping Forest, on June 5th, 1908, and is now in Mr. South's 

 collection. As is well known, this species varies a good deal 

 in the precise position and thickness of the median line (or 

 shade), and I myself have one pretty specimen in which it is 

 thickened Just as in Mr. Betts's. But what gives to the new 

 aberration its distinctive charm is that the entire space between 

 this line and the postmedian on both wings is suffused with 

 smoky, resulting in the formation of a definite postmedian band, 

 which is faithfully brought out in the figure. The under side 

 shows the same peculiarity, though more faintly. The only 

 specimen previously known to me which could possibly be 

 described as "banded" is that figured by Barrett on Plate 329, 

 fig. Ic, of his 'Lepidoptera of the British Islands,' in which the 

 dark shading that accompanies the median line is in-oximal, 

 not distal. On the other hand, it is of interest to note that 

 a specimen of the allied Z. 'punctaria, which was sold in the 



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