VESTITURE 71 



Aedes are derived from basal lobes of the side-pieces, but have reached a dif- 

 ferentiation of structure such that we consider them as separate organs, while we 

 do not so consider the similarly derived structures of Mansonia. In the Culex 

 line we find two simple forms, dyari and melanurus. In these the side-pieces 

 are simple with basal lobes only. The unci and harpes are normal while the 

 harpagones are undeveloped or indicated by a division at the base of the harpes. 

 This is essentially the structure of Culiseta, etc. But in this line the harpagones 

 arise as division from the base of the harpes and not as basal lobes of the side- 

 piece. In Culex proper and its derivatives CarroUia and Lutzia both harpes and 

 harpagones are progressively notched and divided into lamellae, the harpes 

 evolving a curved basal branch and the harpagones becoming divided. The unci 

 are not recognizable in these highly developed forms. The side-pieces of Culex 

 generally bear a lobe near the middle which carries setge or filaments and gen- 

 erally a leaf-like appendage. The Deinocerites group is apparently a develop- 

 ment from Culex in which one of the lobes of the harpagones has grown out into 

 a long spatulate process. The clasp-filaments are thickened and hirsute, some- 

 what as in some Culex, and there are a number of smaller modifications render- 

 ing the type distinct in appearance in this line. 



THE SCALES. 



It has already been stated that the wings bear scales along the veins and on 

 the margins. The body and the legs, proboscis and palpi of mosquitoes are 

 always more or less scaled. Scales are modified hairs. Among the least special- 

 ized mosquitoes, the Anopheles, we find in the body vestiture of the different 

 species an imperceptible transition from hairs, through " hair-like " scales, to 

 well-differentiated scales. The scales differ greatly in form and size on different 

 parts of the body. They also show important specific differences and may even 

 present peculiar characteristics within a certain group. The color of the scales 

 in great measure gives the different species their characteristic appearance and 

 upon vestiture-coloration specific identification largely depends. There is great 

 range in the coloration of the scales. Many mosquitoes show only dull colors, 

 such as black, brown, and dull reddish or yellowish shades, variegated with white. 

 Others show a pattern of silvery or golden scales, while still others are clothed for 

 the most part with scales of brilliant metallic blue, green or purple. 



Theobald, who has utilized to the utmost in his systematic work the character 

 of the scales, in Genera Insectorum, Culicidae (1905), enumerates seventeen 

 types of scales, as follows : " 1, Flat or spatulate scales ; 2, Broad Mansonia 

 scales ; 3, Broad Aedomyia scales ; 4, Curved hair-like scales ; 5, Karrow-curved 

 scales; 6, Spindle-shaped scales; 7, Small spindle-shaped scales; 8, Inflated or 

 parti-colored scales; 9, Pyriform scales; 10, Upright forked scales; 11, Twisted 

 upright scales; 12, Lanceolate scales ; 13, Linear scales; 14, Tseniorhynchus-like 

 scales; 15, Melanoconion scales; 16, Cycloleppteron scales; 17, Heart-shaped 

 scales." In addition Theobald has introduced other terms, such as "fan- 

 shaped," " long twisted " and " obovate " and he has differentiated further by the 

 use of adjectives so that his distinctions become highly complex and often very 



