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the cross veins and the darker scaled wings, from Rhodesiensis by the orna-
mented wing fringe and the cross veins, and from Superpictus by its darker hue
and ornamented fringe."

       Before, however, it would be possible to place such reliance as this on the
value of this character as a means of distinguishing species, it must be shown
that the relative position of the cross veins to each other in any species is
always constant. If it can be shown that in any species the relative position of
the cross veins is not constant, then of course its value as a distinguishing
character is very much lessened.

       In order, therefore, to test this point I examined a number of specimens of two
well known species of anopheles, viz., A. Culicifacies and A. Rossii, to ascertain
whether any marked variations occur in the relative positions of the cross veins.
The results of my examinations are given in the diagrams below (Fig. 8),
and it will be seen that in the same batch of both these species very marked
variations are found, so that, in my opinion, this character does not appear to
be sufficiently constant to enable it to be used for the separation of species.

[NLS note: a graphic appears here - see image of 75022502.tif]

Fig. 8.—To show variation in the relative positions of the transverse veins of the wing.

a,b, c, d. A. Rossii (20 examined).        |         e, f, g. A. Culicifacies (15 examined).

The apex of the wing is towards the right side in each figure.