30 FOSSIL BUTTERFLIES. 



downward in a position the reverse of that of repose. The fore wing covers 

 the hind wing as in nature, but to such an extent as to conceal the greater 

 part of it; the guttered portion of the inner margin of the hind wings is 

 almost fully expanded, but apparently has a fold next the submedian nervure. 

 The fringe of the fore wing seems to be gone, but that of the hind wing is 

 preserved nearly throughout. Head, fore and middle legs, wings of the right 

 side and abdomen are wholly wanting. 



The upper surface of the wings is, therefore, the part which attracts most 

 attention. That it is the upper and not the under surface which is exposed to 

 view is shown by the relation of the wings to each other (PL I, fig. 10), by 

 their unquestionable attachment to the thorax, of Avhich we certainly see only 

 the upper portion with its smooth arched dome marked by the sutures which 

 separate the portions which compose it; and by the design itself of the wings, 

 which is such as pertains to the upper rather than to the under surface of 

 butterflies of this group. These markings are most wonderfully preserved; and 

 the careful and prolonged study I have given every part of the fossil has 

 enabled me to separate, with a considerable degree of certitude, the markings 

 which appertain to the fore wing and those which belong to the hind wing. 

 Those of the latter are generally to be traced through the semi-diaphanous fore 

 wing and are given in PL I, fig. 8. One is aided greatly in this investigation 

 by following the lines and series of markings which extend over both the ex- 

 posed and covered portions of the hind wing; and then by comparing the fainter 

 and obscurer tints of the covered portion with equivalent marks on other parts of 

 the stone covered by both the wings; in this way the markings of the hind wing 

 may be separated from those of the front wing, but subject, certainly, to some 

 degree of doubt. In the figure upon the plate (PL I, fig. 8) the portions to 

 which the least degree of doubt attaches are the outer halves of the two wings. 

 I am inclined to consider these as almost absolutely accurate. The parts on 

 the other hand which are more likely to be inaccurate are the basal halves of 

 the median interspaces of the fore wing and the contiguous portion of the 

 medio-submcdian interspace. Assuming, however, that the drawing faithl'iilly 



