72 MOSQUITOES OF NORTH AMERICA 
vague. In many cases intergrades between the different types of scales occur so 
that the application of the terminology becomes necessarily a matter of opinion. 
In fact the differences in the conception of these terms as employed by different 
authors has brought about great confusion in the systematic literature. 
Part of the above terms are self explanatory, others can hardly be interpreted 
without recourse to specimens. The wing-scales show the greatest diversity and 
have been utilized the most and eleven of the types enumerated above, and their 
modifications, are employed by Theobald as wing-characters. Along each wing- 
vein there are two paired series of scales and the scales of these two series often 
differ greatly in form and size. The non-biting Culicide of the group Core- 
thrine show the most primitive condition of wing vestiture. In Chaoborus the 
scales along the wing-veins are long and hair-like and the two series are not 
differentiated. Among the biting Culicide the Anophelines show the most 
generalized condition. In most species of Anopheles the scales along the veins 
are narrow, lanceolate, and, while there are distinctly two series, the scales of 
these series are often much alike. In other forms of Anopheles there is some 
differentiation, the scales of the lower series being smaller, shorter and less 
divergent. In Anopheles grabhamii the scales are much broader but of the 
lanceolate character; irregularly scattered among these, and with a tendency 
towards grouping, are larger and darker very broad scales, their apices broadly 
rounded or subtruncate. These large, broad scales are the “ Cycloleppteron 
scales ” of Theobald and are said by him to be inflated; they are, however, flat 
like other scales. 
The wing vestiture is remarkably diversified in Uranotenia. On nearly all 
the veins one of the series consists of small, truncate scales arranged in a single 
row and overlapping. On the outer part of the wing the veins also have lateral 
series of large scales and these differ in shape on some of the veins. Finally on 
the basal portion of the fifth vein there is, in most species, a double series of very 
broad small scales of a silver-blue color. In some species the scales on certain 
parts of the wing are white. 
In Culiseta the wing scales are narrow and in two double series along the 
veins. The lower series are of smaller shorter scales, closely applied to the veins ; 
the upper series consists of long and very narrow outstanding scales. A very 
unusual feature occurs in certain species of this genus; the anterior cross-vein 
bears scales. In most species of Culex the appearance of the wing is similar to 
Culiseta. There are, however, three double series of scales outwardly on some of 
the veins. The long scales are usually narrow and blunt or truncate at the tip; 
these are the “ linear ” scales of Theobald, and we have termed these “ ligulate.” 
In many forms the scales are broadened and rounded at their apices and there is 
an increased tendency to crowding towards the apex of the wing. This con- 
stitutes the so-called “ Melanoconion scales” of Theobald; however these are 
not separable as a distinct type, but, through different species, intergrade with 
the ordinary Culex scales, and the tendency to crowding towards the apex of the 
wing is a very general one. The smaller scales when broad are often obliquely 
subtruncate. In most species of Aédes the wing scales are entirely similar to the 
