UKBICOLA COMMA. 155 



manage to see anything but loose members, although I took it for 

 granted that they must be connected with one another in some way; 

 but at last I succeeded in getting several uninjured scales, by boiling 

 them in a solution of potash. Thereby it was ascertained that each of 

 such hairs, or scales, reaches a length of 0"27mm.-0*35mm. and a 

 breadth of O004mm. The members, of which the scales consist, vary 

 much in length (0'013mm.-0-054mm.) and in form. The lowest (fig. 

 19d, g) is always drawn out into a stalk which sticks into the wing- 

 membrane, and the uppermost (fig. 19a, c, f) is usually smaller than 

 the rest, and has a small blunted tip. The joints, i.e., the points where 

 they join, of the members vary in appearance according to the side 

 from which they are viewed, sometimes they look like two small knots 

 projecting outwards on each side and separated in the middle by a 

 furrow (fig. 19c), sometimes one sees only one (fig. 19b), this latter case 

 resulting certainly from the fact that one knob covers the other when 

 viewed from the side. How the members are really connected, whether 

 by a fitting of the knobs one into the other, or whether by a thread 

 running through all the members, I have not been able to discover 

 with certainty. The upper surface, where the androconia are fixed, 

 appears, on the denuded wing-membrane, quite opaque, on account of 

 the closely compressed fastening-points. These are so close together that, 

 on a moderate computation, there would be some 50000 to each square 

 millimetre, and, as the surface on which they are fastened amounts to at 

 least seven-eighths of a square mm., there would, therefore, not be less 

 than about 44000 androconia. Now if we reckon the upper surface of 

 each androconium at 0*0036 sq. mm., then they make altogether an 

 upper surface of about 160 sq. mm., i.e., a surface greater than that 

 of the entire forewing. In colour the $ differs in its less size and 

 distinctness of the yellow spots " (Aurivillius). 



Genitalia. — Described and figured by Scudder (Mem. Bost. Soc. 

 Nat. Hint., iii., p. 350, pi. xi., figs. 10-11). Upper organ strongly 

 arched, rather deeply sulcate above posteriorly ; hook one-third the 

 length of the centrum and slightly curved downwards ; together with 

 the centrum it is very broad at the base above, tapers roundly to a 

 rounded apex, and is but little longer than broad ; viewed from the 

 side, the hook is nearly equal, the apex pointed beneath ; lateral arms 

 equal, cylindrical, tapering a little at the tip, not very widely separated 

 from the centrum at their base, curving slightly upward, of equal 

 length with the hook. Clasps about twice as long as broad, extending 

 fully as far back as the upper organ, narrowing pretty regularly from 

 the base, the upper margin incurved and deflexed, the posterior border 

 rounded, extending beyond the apical tooth, and of a somewhat ragged 

 outline ; the preapical tooth is somewhat longer than the apical, but 

 is incurved to such a degree as to appear of the same length on a 

 lateral view ; otherwise they are both nearly straight, upturned and 

 narrowly separated by a very deep rounded excision ; the irregularly 

 serrated lamina supporting the inner anterior edge of the apical tooth 

 possesses five or six slight serrations, and the lamina terminates 

 abruptly opposite the anterior edge of the preapical tooth. [The 

 appendages of the northern form, catena, seem to differ from those of 

 the normal type only in sometimes having the preapical tooth no 

 longer, or but very slightly longer, than the apical, and in that the 

 two teeth are always separated by a slightly wider interval than in the 



