26 ILLINOIS BIOLOGICAL MONOGRAPHS [258 



dorsal and lateral regions of Megilla, but on the lateral aspect of the eighth 

 segment there is a verruca. Verrucae are found almost exclusively on 

 Scymnus, while in Microweisea they are very small and closely approxi- 

 mate the form of chalazae. Verrucae are also found on the ventral por- 

 tion of the ninth segment in practically all genera of the Coccinellidae, the 

 only exceptions being Hyperaspis and Scymnus. Chalazae are found on 

 the dorsal shield and on the shield-like spots of the mesothorax and meta- 

 thorax of Hippodamia, Megilla, Anatis, Adalia, and Coccinella. There are 

 also a few on the prothoracic shield of Scymnus. The same type of arma- 

 ture is present on the ventral parts of the thoracic and abdominal seg- 

 ments throughout the family and on the lateral portions of the eighth and 

 ninth segments of Adalia, Megilla, and Scymnus. They are usually sur- 

 rounded by a group of finer setae. In Hyperaspis and its allies the arma- 

 ture of the body has been so reduced that it is composed of setae forming a 

 hair-like covering over the entire surface. The ventral surface of all of the 

 members of the family is provided with setae rather than scoli, parascoli, 

 senti or strumae. Even in those genera where chalazae or verrucae are 

 found on the ventral surface, setae are also abundant. The type of arma- 

 ture of the Coccinellidae shows a steady and unbroken series of changes in 

 specialization from the generalized scolus to a seta through the reduction 

 or the disappearance of parts. 



