1933 ] 
Mermis Parasitism in Ants 
21 
ture, I can find no evidence that the specimen has ever borne 
developed wings. The tegulse are normal, but each fore 
wing is represented by a small, hard, jet-black tubercle. 
There is no trace of a hind wing on the left side, but the 
right hind wing appears to be represented by a minute 
rounded tubercle near the lateral border of the metanotum. 
If my interpretation is correct, we may suppose that the 
reducing effect of the Mermis on the wings is very much 
greater in Myrmecia than it is in the mermithogynes of 
Lasius, which have these appendages merely reduced to 
about half or one-third their normal size. 
I have not seen the normal female of rubra, which is de- 
scribed by Clark as very slightly larger than the worker 
(19-23 mm.) as contrasted with the female of the typical 
M. forficata Fabr., which is considerably larger than its 
worker. I therefore compare the dimensions of the mer- 
mithogyne with those of the females of the very closely re- 
lated forficata, lucida Forel and regularis Crawley. A lucida 
female from Hobart, Tasmania (G. H. Hardy) measures 
nearly 20 mm., its gaster 6 mm. in length and nearly 4 mm. 
in dorsoventral diameter, the head including the mandibles 
6.5 mm., in diameter through the eyes 4 mm. Normal fe- 
males of forficata from New South Wales and Victoria 
measure about 22 mm., the gaster nearly 7 mm., dorsoven- 
trally nearly 4 mm., the head including the mandibles 6 
mm., through the eyes 3.8 mm. The average female of 
regularis from Southwestern Australia measures 18-19 
mm. in length ; gaster 6 mm., dorsoventrally 3.5 mm. ; head 
with mandibles 6 mm., through the eyes nearly 4 mm. The 
rubra mermithogyne measures nearly 24 mm. ; its gaster 9 
mm., dorsoventrally 5.5 mm.; the head with mandibles 6 
mm., through the eyes 3.6 mm. This specimen therefore 
shows little modification as the result of parasitism com- 
pared with normal females of the closely allied species, ex- 
cept in the greater size of the postpetiole and gaster and its 
almost complete aptery. Probably, however, the head and 
thorax are distinctly narrower than in the unparasitized 
rubra female. The extreme, red bases of the gastric seg- 
ments are exposed and through them portions of a coiled 
Mermis are distinctly discernible. 
