NO. 3557 SUBGENUS CULEX—BRAM 81 
mean number of teeth; M is the mode; and R is the range in the 
number of teeth for the given area. N is the number of observations 
in each sample. Each observation consists of the number of teeth 
on only one side of the mesosome. Thus, a single individual could 
contribute two observations to the sample. In 35 of the 97 specimens 
examined, there was a difference in the number of teeth on each side 
of the mesosome. Variation in the number of teeth of specimens 
examined in this study ranged from three to 12 and the number 
appeared to be larger on the west coast and smaller on the east coast. 
This indicates that the number of teeth on the median process of the 
mesosome is not a significant character and since there are no other 
major differentiating characteristics between these two species, C. 
tisseuillt is here placed in synonymy with C. mollis. 
Although a generalized arrangement of appendicles on the apical 
lobe of the basistyle exists, this species is readily distinguished from 
all other members of the subgenus by the characteristic, extremely 
large, T-shaped ventral cornu. 
SALIENT CHARACTERS.— Adult female: See table 1. 
Male terminalia: Basistyle conical, slightly longer than twice the 
basal width; clothed with fine setae in addition to the normal, long 
setal pattern. Apical lobe of the basistyle prominent, undivided, and 
also clothed with fine setae. Appendicles of the apical lobe as follows: 
basal rod strong, straight, and pointed at the apex; median rod longer 
and broader than basal rod, and prominently hooked; apical rod 
longer than median rod and also prominently hooked; leaf moderate in 
size, obovate; two accessory setae present, one fine and hooked distally, 
the other very strong, longer than the leaf, and gently curved. Disti- 
style normal. Tenth sternite crowned with a dense tuft of short, 
pointed spines; basal arm moderate in length and curved; two cercal 
setae present. External process gradually tapering to a point, 
reaching slightly farther than the ventral cornu. Ventral cornu 
extremely large, T-shaped, and distinctly separated from the teeth 
of the median process. The ventral cornu is quite variable in size and 
general conformation; figures 24c—f demonstrates some of the varia- 
tions in shape which this structure may assume. Median process 
with three to 12 sharply pointed, distinctly separated teeth. Geo- 
graphical variation in the number of mesosomal teeth may be seen in 
figure 23. Examination of the mean, mode, and range of collections 
from various areas indicates that specimens collected on the west 
coast of South America have considerably more teeth than those 
collected on the east coast. Basal process short, straight, and bluntly 
rounded. 
Larva: Antennal tuft located in a constriction near the outer third; 
antennal shaft sparsely spiculate basally. Postclypeal head hair 4 long, 
231-52! C76 
