266 



ELEMENTARY STUDIES IN INSECT LIKE 



means of flight, they are commonly called the wings. 



(Fig. 202.) 



THE ABDOMEN. 



Among writers upon this subject there exists a differ- 

 ence of opinion concerning the number of segments com- 

 posing the abdomen. It will be evident to the observer 

 here, upon a careful examination, that there are eight 

 segments on the dorsal aspect of the abdomen of the 

 female, and nine clearly shown on the same portion of 

 the male. As will be seen from Fig. 202, we have con- 

 sidered the .segments caudad of segment eight in the 

 female, and segment nine in the male, as parts of the 

 dorsal portion, and have numbered them accordingly. 



The First Segment- - The ventral portion of this seg- 

 ment is dovetailed into the metasternum, and by some 

 authors has been considered a part of the metasternum. 

 The ventral portion is widely separated from the lateral 

 portion of the same segment, by the insertion of the 

 hind leg. 



The Auditory Organs. - - Just 



dorsad of the leg in this seg- 

 ment is to be found on each 

 side an oystershell-shaped open- 

 ing, covered by a membrane. 

 These are the organs of hearing, 

 or auditory organs, and the mem- 

 brane covering them is the tym- 

 panum. 



Second to Eighth Segments 

 The second to the eighth seg- 



FIG. -203. Exterior view of 

 auditory organ. Sp, spiracle. 

 Clear space is tympanum. 

 Small dark body in center is 

 vesicle, which is connected by 

 vein to ganglion shown at 

 right. Enlarged fifteen times. 



ments are each ring -like in 

 form. 



