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XII. The Rein-sheath in Plebeiid Blues : a correction of 

 and addition to Paper VI. By T. A. Chapman, 

 M.D., F.Z.S. 



[Road October 4th, 1916.] 



Plates LXXV-LXXIX. 



The last paragraph of my paper on " The Pairing of the 

 Plebeiid Blue" Butterflies " contains one very confident 

 but quite erroneous statement, that I desire to correct. 



The material I was dealing with was scanty, and I did 

 not know how to obtain any additional supplies. I was, 

 however, so dissatisfied with the position in which I had 

 left the matter, that I determined to follow it further. 



I am now able to say something definite, and I hope 

 correct, about the remarkable structure referred to. As 

 a matter of fact, the sheath does consist of scales, but 

 scales of such curious form and disposition that I am not 

 prepared, whatever others may be, to blame myself 

 severely for failing to recognise them as such, having 

 preserved only two or three specimens. 



The sheath, then, consists of scales, whose points of 

 attachment are the "points" with which the surface of 

 the rein is studded. These points are very small, quite 

 unlike the usual sockets from which scales usually arise, 

 but more like, as I described them, the traces of abortive 

 hairs or scales. They must be the points of origin of the 

 scales of which the sheath consists, but from which the 

 scales so readily separate that it may be doubted whether 

 they are at all attached to them, after the butterfly has 

 emerged from the pupa. The scales are of a very un- 

 usual nature. The end, by which each was presumably 

 attached to the surface of the rein, tapers to a point, that 

 looks rather like a distal than a proximal end. The body 

 of the scale is so curled and twisted as to be difficult to 

 make out as to size or form; the distal end appears to 

 be rounded. The twistings and curlings of neighbouring 

 scales are so intertwined, as to obscure each other, and 

 are the means that hold the scales together to form a 

 cylinder. 

 TRANS, ent. soc. lond. 1916.— PARTS III, IV. (APRIL 17) x 



