1 66 



The Orders of Insects 



()l d, e). There are six evident abdominal segments, 

 whereof the fourth is often much longer than the 

 others ; the first segment bears a ventral tube pos- 

 sibly formed by the union of a pair of appendages. 





:#. .% 



Fig. gi. — Springtails. a. Smynthurus ; b. Cyphoderus ; c. scale ; d. e. foot 

 claws ; f. tip of spring ; g. Lipura, head and first two body-segments, right 

 mandible shown within head ; i. post-antennal organ ; //. maxillje, front 

 pair. All Magnified. From Carpenter, Irish Naturalist, vol. 6. 



In some springtails a pair of long delicate vesicles are 

 at times protruded from the ventral tube ; this tube 

 perhaps assists the insect to walk on smooth vertical 



