22 ILLINOIS BIOLOGICAL MONOGRAPHS [254 



of chalazae arranged in a transverse row; those near the meson are the 

 ventral chalazae and those on the lateral margin are the ventrolaterals. 

 Each chalaza is surrounded by a small group of setae. 



The sixth, seventh, and eighth abdominal segments are as long as the 

 preceeding but narrower. The pinacula at the bases of the dorsal senti 

 have become fused on their mesal margins and appear to be dumb-bell- 

 shaped. The dorso-lateral senti are shorter than those of the preceding 

 segments and their pinacula are very much reduced. The lateral aspect 

 of each of these segments is similar to that of the preceding, except that 

 it is considerable smaller. There is a small lateral sentus with a very small 

 pinaculum on the lateral aspect of the sixth and seventh segments and 

 almost a rudimentary sentus on the eighth segment which is without a 

 pinaculum. In Epilachna the lateral aspect of the seventh segment is 

 provided with a distinct parascolus rather than with a scolus as in the 

 sixth; while the eighth segment has a struma and the ninth only a 

 few chalazae. There is a distinct chalaza surrounded by a group of fine 

 setae ventrad of the lateral sentus of each segment. This chalaza and the 

 setae represent a paralateral group. Each sternum is as wide and as 

 long as its respective tergum. The cuticle of each segment is soft and 

 bears four distinct chalazae arranged in a transverse row. Each chalaza 

 is surrounded by a group of small setae. The ventral groups are adjacent 

 to the ventro-meson and the ventro-lateral groups are located near the 

 extreme lateral margin of each segment. The coriae between the seg- 

 ments are distinct. 



The ninth abdominal segment is small, cylindrical, slightly narrower 

 and shorter than the eighth. The tergum is inclined ventrad at an angle 

 of about thirty degrees. The dorsal senti are absent and in their place 

 there are distinct dorsal strumae. The dorso-lateral senti are also reduced 

 to strumae and located near the lateral margin of the tergum. The lateral 

 aspect is small and the senti are wanting, but there is a prominent chalaza 

 surrounded by a group of setae near the ventral margin. This group 

 represents the lateral group; the paralaterals are wanting. The ninth 

 sternum is short, deeply emarginated on the caudal margin, and bears four 

 chalazae arranged in a transverse row. The ventral chalazae are located 

 adjacent to each other and the ventro-meson and are surrounded by a 

 group of fine setae; while the ventro-lateral are without setae. Through- 

 out the family the ninth segment shows the greatest variation in its size, 

 shape, and structure. In Chilocorus the ninth abdominal segment is 

 rectangular, about twice as wide as long; its anterior margin is little if any 

 narrower than the eighth segment; the caudal margin is sharply rounded 

 and never serrated; and its lateral aspect bears chalazae and setae. The 

 lateral aspect of the ninth segment in Epilachna is rectangular, about 

 twice as wide as long, much narrower than that of the eighth segment, and 



