1928 ] 
Notes on three Abnormal Ants 
53 
andromorph which I took in the summer of 1927 at Boulder, 
Colorado. On August 10th while collecting along the foot of the 
ridge between Gregory and Bluebell Canyons, I found a nest of 
Formica nitidiventris, Em. containing an ant with wings on the 
left side only. The insect was in the upper galleries of the nest 
in the company of twenty or thirty workers. The latter fled as 
soon as the covering stone was raised, leaving the ergatandro- 
morph whose slower movements hindered its escape. When 
allowed to walk on a relatively smooth surface it circled to the 
right. 
Fig. 1 shows the more important features. The left half of 
the insect is male, the right worker, although in the head and 
thorax the junction does not occur at the mid-line of the body. 
The structures of the opposite sides of the head appear to be 
quite typical as regards their respective castes. The right 
(worker) antenna has the requisite twelve joints of the customary 
shape and size. The right eye and mandible differ in no way 
from those of the normal worker. On the left (male) side the 
eye is much larger, the mandible greatly reduced and the antenna 
of thirteen joints, all usual male features. The clypeus is twisted 
to the left, a result of the obvious discrepancy in the length of 
the gense (Fig. 2.) Aside from the major structural differences 
in the males and workers of this , subspecies there are certain 
pecularities of color and pilosity characteristic of each. Thus 
the head and thorax of the normal worker are a rufous brown 
and those of the male a deep brownish black. In Figs. 1 and 2 
this darker male coloration has been indicated by stippling. 
Referring to 2 it may be seen that the entire clypeus and most 
of the vertex and occiput are of worker origin. There is also a 
curious projection of worker tissue which runs downward from 
the vertex to the upper border of the eye. All three ocelli occur 
in worker tissue and all are of the small size characteristic of the 
worker. 
Taking into consideration the radical differences in the 
thoracic structured of the male and worker the thorax of the 
mosaic is less mixed than would appear at first sight. The pro- 
thorax of the worker has fused fairly evenly with the pronotum 
of the male. The mesothorax is united with the scutum, the 
