112 
ZOOLOGY: W. M. WHEELER 
I have studied Monomorium is the most instructive in this connection, 
because at least two of its species exhibit a normal and hitherto un- 
suspected condition of subaptery in the female. Some years ago ForeP 
described a Monomorium rothsteini from worker specimens received from 
Queensland, Australia, and later distinguished two varieties of it, 
humilius,^^ from Tennant Creek, Central AustraHa and leda,^^ from 
northern Queensland. During December, 1914, I observed many colo- 
nies of rothsteini in various localities in Queensland. The workers of 
this species store their subterranean nests with small grass-seeds and 
are therefore harvesters, like the species of Holcomyrmex, now regarded 
as a subgenus of Monomorium. Among a lot of ants recently received 
from the Museum of South AustraHa I find a large series of cotypes of the 
var. humilius comprising 14 specimens of the female, which was unknown 
to Forel. This phase measures 7-7.5 mm. and has long, well-developed 
wings (6.8-7 mm.). In the same collection I find three series of a closely 
alhed species, which I shall describe in another place as M. subapterum 
sp. nov. Two of the series, representing the typical form of the species^ 
comprise numerous workers, 10 males and 10 females (5 dealated) taken 
by Mr. W. D. Dodd on the Harding River in North West Australia 
and one female and several workers taken by the same collector at 
Derby in the same region. The remaining series represents a color 
variety of subapterum, which I shall call bogischi var. nov., comprising 
several workers and four females (three dealated) from Point Wake- 
field, South Australia (G. P. Bogisch). The winged females in all three 
series measure 6.5-7 mm. and agree in having very small wings, measur- 
ing only 3 mm., and a distinctly smaller thorax than rothsteini. There 
are other specific differences which need not be discussed at the present 
time. Figs. 1 and 2, drawn to the same scale, show the differences in 
wing and thoracic structure between the females of the two species, 
corresponding to what may be called the macronotal, winged and me- 
sonotal, subapterous types respectively (1 and 2, p. 114). The males of 
M. rothsteini and subapterum show no differences in the size and develop- 
ment of the wings, which in both are large and of the usual structure. 
There can be no doubt that the dealated females of two of the series 
of subapterum originally bore small wings like the nondealated individuals. 
The fore wings have a singular truncated apical border, as if they had 
been trimmed with scizzors, and this appearance is accentuated by the 
fact that the membranes are as thick at the border as at the base. It is 
certain, however, that the wings have not been reduced to their present 
form by the mandibles of the ants. The venation is abortive, only the 
submarginal vein being distinct, although the fore wings show faint 
