Supplement to Harvesting Ants and Trap-Door SpidersMoggridge, John Traherne
Science
Supplement to Harvesting Ants and Trap-Door Spiders
Moggridge, John Traherne
Ants; Trap-door spiders
The _eyes_ are in two transverse lines, forming an area whose length
is rather less than 2-1/2 times its width; the foremost line is
curved, and the curve directed backwards, the hinder one is also
curved and in a similar direction, but less strongly, looking
laterally the extreme margin of the four eyes of the hinder row forms
a straight line. Considered as in pairs, those of the fore-central
pair are separated by an interval equal to that which separates
each from the fore-lateral and hind-central nearest to it; the
fore-laterals are divided by about two and a half diameters; they are
the largest of the eight, only slightly however, in some examples,
larger than the hind-laterals. Each of them is separated from the
hind-lateral on its side by not quite half the diameter of the
latter, and each hind-lateral is very nearly but not quite contiguous
to the hind-central on its side; the hind-centrals are roughly
rounded, smallest of the eight, though in some examples equal in size
to the fore-centrals, and are separated from the fore-central nearest
to it by about one diameter, which gives a clue to the absolute
distance between the eyes of the foremost pair. The four lateral eyes
are oval, the fore-centrals round; those of the foremost row are
darkish coloured, while those of the hinder row are pearly white.
Although it is of great importance to observe as accurately as
possible the relative position and size of the eyes, yet we must be
prepared to find exceptions to the rule derived from the most exact
measurements in any individual instance.
In the present species the above conclusions, as to position and
size, are drawn from a consideration and comparison of 20 examples,
and are, it is believed, pretty true, but yet in one example, one
of the hind central eyes was but half the size of the other, and
in another example one of the same eyes was but one-fourth of that
of the other, a mere dot in fact, and the relative size of the
respective lateral eyes of the two rows do not appear to maintain
exactly the same proportions in all individuals. The height of the
clypeus appeared to be as nearly as possible half that of the facial
space.
Public-domain text, read in full here on John Shaqi.
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