ANOPHELINES OP MEXICO, CENTRAL AMERICA AND WEST INDIES 
91 
of very large leaflets is present, with or 
without a smaller pair. In the group Arri- 
balzagia, the number of pairs of leaflets is 
variable, but the largest pair differs in 
shape and size from the smaller pairs. Sub¬ 
genus Nyssorhynchus is easily recognized 
because the dorsal lobes of the claspette are 
fused to form a single median structure, 
the form of which is characteristic in most 
of the species. In subgenus Kerteszia, the 
position of the internal spine, lying as it 
does between the parabasal and the two 
accessory spines, is characteristic. 
A rather complete knowledge of the 
characters of the male terminalia is re¬ 
quired for the separation of the species of 
the subgenera Nyssorhynchus and Kertes¬ 
zia. As Root has well said, “The adult 
markings of species of this subgenus 
(Nyssorhynchus ) are unusually variable, 
and in working out the fauna of a region 
which has not been carefully studied previ¬ 
ously, it is essential to base identifications 
on larval and hypopygial characters, which 
are comparatively stable, instead of on the 
variable characters of the adult colora¬ 
tion.” Because of limitations of space, it 
is impossible to do more than to indicate 
the characters by which species may be 
identified. Students desiring to obtain 
further information on the use of the char¬ 
acters of the male terminalia are referred 
to the separate works listed in the bibli¬ 
ography. 
Larval Characters 
In many instances, particularly among 
the neotropical species, the larvae show bet¬ 
ter differential characters than the adults. 
This is particularly true of the subgenus 
Nyssorhynchus. The principal characters 
used in differentiating species are: the 
form and spacing of the anterior clypeal 
hairs of the head; the shape of the inner 
hair of the prothoracic submedian hair- 
group ; the shape of the pleural hairs; the 
shape and number of the lateral abdominal 
hairs; the number of pairs of palmate hairs 
of the abdomen and the form of the indi¬ 
vidual leaflets; the shape and arrangement 
of teeth of the comb of the eighth abdom¬ 
inal segment; and in a few species, the 
peculiarities of the form of the respiratory 
apparatus. A number of other characters 
are of use in differentiating certain species, 
but most of the larger groups may be sepa¬ 
rated on the characters enumerated above. 
Pupal Characters 
Very little attention has been paid to the 
pupal characters of the Neotropical 
Anophelines, as in most cases the differ¬ 
ences are very slight and variable. In 
genus Chagasia, series Cycloleppteron, and 
group Arribalzagia, however, the pupal 
trumpets have characteristic shapes, and 
afford better means of separation of species 
than either the larvae or the female adults. 
In one important species of subgenus 
Nyssorhynchus, A. darlingi, the pupal 
trumpets are unique in form, and afford, 
excellent characters for identification. 
Characters of the Female Adults 
A large number of characters has been 
used to define the various genera and sub¬ 
genera, and smaller divisions. Probably 
one of the most useful gross characters is 
the color of the legs. The tarsi of all the 
legs are black in Stethomyia kompi, and in 
the 10 species of the series Anopheles. In 
the series Cycloleppteron and group Arri¬ 
balzagia, the legs are speckled and banded 
irregularly with spots of white or yellow. 
In the subgenus Nyssorhynchus, the hind 
tarsi have the first segment black, the base 
of the second segment black, the apex white, 
while all the remaining three segments are 
either pure white, or have a narrow black 
basal band on the fifth segment. 
The scaling of the body is another impor¬ 
tant group character. The species of the 
series Anopheles have no scales on the dor¬ 
sum of the abdomen. Those of the group 
Arribalzagia have prominent lateral scale 
tufts on the abdominal segments, as do the 
species of subgenus Nyssorhynchus. Ker¬ 
teszia lacks these scale tufts, no dorsal 
abdominal scales being present except in 
one species, which is not found in our area. 
The wing-pattern, composed of aggrega¬ 
tions of scales of different colors, disposed 
along the wing-veins, is of use in determin- 
