4 Messrs. H. J. Elwes and J. Edwards on 
excellent method devised by Mr. Salvin, who by means 
of a combination of cardboard and cover-glass produces 
a cell for balsam-mounting which possesses all the ad- 
vantages of the ordinary cell, and moreover may be 
pinned in the cabinet; the chief points in the latter 
method are the rendering of the cardboard impervious to 
the mounting fluid by soaking it in a solution of white 
shellac,* and the provision of a channel by which air- 
bubbles may be got rid of, and the mounting fluid 
augmented, if perchance any should happen to be 
absorbed by the cardboard. These transparent pre- 
parations are undoubtedly better and more scientific 
than the products of the rough-and-ready plan before 
described, which has been adopted in preparing the 
material for this paper, since they illustrate the arrange- 
ment and ultimate structure of the parts to perfection ; 
but they only admit of examination in one aspect, that 
at right angles to the plane of the cover-glass, and every 
one has not the time and ability necessary for their pre- 
paration; therefore, so far as the mere question of 
identifying species is concerned, some persons may give 
the preference to the dry-mounted separate parts. 
A word as to the figures which accompany this paper. 
They are all more or less diagrammatic, being simply 
intended to convey to the mind an idea of the contour 
of the object under a given aspect; all the shaded 
figures are drawn to the same scale, correct propor- 
tion having been secured by the use of the camera lucida, 
and the amount of amplification never exceeds that 
which may be obtained with a good hand-lens. Figures 
of this kind seem more likely to answer the purpose than 
more complex representations of the parts in situ from 
specimens mounted as transparent objects for the micro- 
scope, whether these are produced by camera drawings 
or photography; we have excellent examples of the 
former in Plate II. of our ‘Transactions’ for last year, 
and of the latter in ‘Tris,’ vol. i., plate xi. 
The species of this genus are of a prevailing brown 
colour, with a large subapical ocellus on the fore wing, 
which reaches its greatest development on the under 
surface, and is obsolescent or wanting on the upper 
surface of the males of certain species, and from one to 
* Gold size answers equally well.—J. E, 
