74 MOSQUITOES OF NORTH AMERICA 



scales of the mesonotum vary much in size and shape. They are sometimes very 

 small and hair-like, or they may be larger and slightly broader and are then the 

 " narrow curved " scales of Theobald. They may be broad, more or less trun- 

 cate at the apex and are then Theobald's " flat or spatulate " scales. There may 

 be broad, flat scales pointed at both ends and these are the " spindle-shaped 

 scales " of Theobald. The scales of the mesonotum may be all of one type or 

 several kinds may be present. The scales may be diffierent in color as vrell as 

 form and thus produce more or less distinct patterns. A curious type of scales 

 is present on the mesonotum of certain species of Bancroftia. These are white, 

 very long, narrow, flat scales arranged in longitudinal rows ; some of these rows 

 are continued over the scutellum, the end scales projecting far beyond its pos- 

 terior margin. The scutellum is covered with scales of similar character with 

 those of the mesonotum. The scales on the scutellum may be broad while those 

 on the mesonotum are narrow. In many species there are areas or longitudinal 

 stripes upon the mesonotum which are devoid of scales. 



The postnotum is usually naked ; in a few Sabethini, however, scales are pres- 

 ent. There may be only a few scales arranged in one or more rows, or the entire 

 postnotum may be covered, as in some species of Sabethes and Sabethimis. 



The pleurae and coxae are generally more or less covered with pale scales, but 

 these are often very deciduous or they may be absent altogether. Sometimes a 

 part of the scales on the pleurae are of another color. 



The abdomen is usually covered with broad overlapping scales. In many 

 Anopheles there is only a sprinkling of hair-like scales ; in others flat scales are 

 present on the last segment, or on all the segments. In certain species of Anoph- 

 eles, and in some other mosquitoes, there are tufts of erect, flat scales on some 

 of the abdominal segments. In certain species of Megarhinus there are long 

 scales which extend laterally as fan-shaped tufts on the apical portion of the 

 abdomen. In a few cases the cerci are covered with scales. 



The legs are covered with scales in all mosquitoes and usually these scales 

 are small and closely applied to the surface. Sometimes the scales are long and 

 more or less raised, usually most pronounced on the hind legs, as in certain 

 species of Psorophora and Lesticocampa. In some cases very long, narrow scales, 

 which extend outward in a plane, are present on certain parts of the legs. These 

 in Sabethes give the well-known " paddle " effect. These paddles involve parts 

 of the tibia and the tarsus. Such paddles may be present on one pair of legs or 

 on all the legs. In Aedeomijia squamipennis the femora are furnished with 

 rough scale-tufts nears their apices. 



The proboscis and palpi are clothed with scales. These are usually small and 

 closely applied, but sometimes they are more or less raised and long and give a 

 shaggy effect. 



In a few cases scales are present upon the clypeus. The tori or globose basal 

 joints of the antennae often bear scales. The first joint of the shaft is densely 

 scaled in Megarhinus and in other mosquitoes still other antennal joints bear 

 scales, but these forms are exceptional. 



