Psyche 
136 
[June- August 
A GYNANDROMORPH OF TETRAMORIUM GUINEENSE 
FABR. 
By William Morton Wheeler. 
Bussey Institution, Harvard University. 
Mr. P. H. Timberlake has had the kindness to send me a 
very interesting gynandromorph of the common tropicopolitan 
ant, Tetramorium guineense Fabr., which was captured June 
19th, 1923 by Mr. E. H. Bryan on Necker Island, some miles 
northwest of Honolulu. Unlike the previously recorded ant- 
gynandromorphs, this insect is a pure example of the antero- 
posterior type, the head being male, the remainder of the body 
female, with perfectly developed wings (Fig. la). I can detect 
no deviation in the structure of the head (Fig. lb) from that of 
the normal male. The antennae are perfectly developed and 
10-jointed, and the details of the sculpture, pilosity and color of 
the normal male are accurately reproduced. The head of the 
normal female, shown in Fig. Ic, is, of course very different. 
The thorax, however, is precisely like that of the normal female, 
except that it is slightly less robust, with the mesonotum a little 
less flattened dorsally, and the metasternal spines are un 
developed. The thorax of the male guineense is very different 
from that of the female, since it lacks the epinotal spines as well 
as the metasternal spines, has a more convex mesonotum and 
mesosternum and the former has Mayrian furrows. The color 
is also darker and the surface much smoother and very differently 
sculptured from that of the female. The legs, petiole, post- 
petiole and gaster of the gynandromorph are precisely as in the 
normal female, even the sting, which is fully exserted, being of 
the same length and structure. The sculpture, pilosity and 
color are also as in the normal female, the thorax, legs and pedicel 
being yellowish ferruginous, the gaster very dark brown or 
blackish, with its extreme base and tip yellowish brown. There 
is every reason to assume that the internal reproductive organs 
are those of the normal female. The wings are whitish hyaline, 
with colorless veins and pterostigma, as in the normal female. 
On looking over the specimens of Tetramorium guineense 
in my collection I find one male from Cagues, Porto Rico with 
