loci THE entomologist's RECORD. 



part of the two red patches on the underside is opposite the upper sur- 

 face-submarginal band, and it is only the tij)s of the red markings which 

 occasionally are reproduced in the yellow area of the upper surface. 

 The submarginal band on the underside is in no part — except perhaps 

 the portion between nervures 7 and 8 — so broad as on the upper surface, 

 but the difference is slight except between nervures 3 and 5. It is 

 particularly important to remark that all the seven specimens I have 

 seen with red inside the submarginal band are females. How far this 

 develojiment of red bears on Mr. Weir's theory, it is hard to say ; it 

 may strengthen it ; it certainly shows a very strong inherent tendency 

 on the part of P. machaon, to develop red scales in the hind wings, and 

 is a 2)oint well worthy of further consideration. 



The remaining })oints of variation in the posterior wings are chiefly 

 of shajje of the markings, and are in a great measure dependent on the 

 size and development of the specimen ; I will refer first to the broad 

 sub-marginal band Avhich varies considerably in width ; in a typical 

 specimen it is broadest from nervure 2 to 4, it then narrows towards 

 the costa, its inner edge being about parallel with the hind margin of 

 the wing ; in some specimens the liand is of equal width u]) to nervure 

 (j, the gain from nervure 4 to 6 being almost entirely on the inside, 

 this converts the inner edge from a curved line to almost a straight one, 

 and considerably lessens the width between it and the discoidal cell, 

 and in some specimens I have, the liand reaches and partly encloses the 

 black patch on the discoidal lunule. The band is densely clothed with 

 metallic blue scales, but has a well maintained border of black on both 

 edges, the outer one being least clearly defined, and in one or two 

 specimens the blue scales almost reach to the extreme edge of the band : 

 the blue scales are usually divided up into six patches by the lines of 

 the nervures, but in one or two specimens they cover the nervures as 

 well, and so become a continuous mass. 



The remaining important feature in the variation of the hind wings 

 is in the black patch on the discoidal lunule, this varies much in size 

 and shape ; one specimen in my own series is entirely without it, others 

 have it very small, and intermediate forms occur to a patch aljout 3 lines 

 by 1 line in size ; a form not uncommonly occurs generally known as 

 the " cell-divided variety," in which this black patch is divided in the 

 centre by a thin yellow streak, this variety" I have found more frequently 

 in (J s than $ s, it is so in my series in the proportion of nine to two. 

 I think this is very likely only accidental, as two or three in Mr. Jones' 

 collection are all $ s. The nervures of the posterior wings are usually 

 but thinly coated with dark scales, but there is occasionally a thickening, 

 especially of the boundaries of the discoidal cell. The submarginal 

 yellow lunules vary in shape and size, usually subordinate to the size 

 of the specimen ; in a very few specimens they are inclined to be 

 squarish patches slightly concave on the top, and entirely losing their 

 lunar shape, in others they are perfect lunules, but generally the lower 

 end is a little the longer, vanishing in a very fine j^oint. The " tail " 

 varies in length, but this also depends in a great measure on the size of 

 the specimen. 



In the upper wings the first point to claim ni}' attention is the 

 occasional possession of a black sjiot near the apex of the wing, in the 

 yellow space between nervures 6 and 7. There is always a black spot 

 in the sjDace above, which I will allude to as the subapical, and the 



