284 



THE BIOLOGY OF INSECTS 



those CoUembola in which the spring is absent in the adult, 

 though the rudiments of that organ appear in the embryo, 

 and remain as vestiges in the newly hatched young. The 

 cuticle of Anurida is covered with minute tubercles which 



Fig. 70. — a, Seashore Springtail {Archiostoma heselsi), side view, X 30 ; 

 b, left frontal region, showing feeler with terminal sense-organ, o, post- 

 antennal organ, p, at its base, eight ocelli behind, X go; c, shin and 

 foot of hind leg, X 240; d, catch; e, spring (dorsal view), X 150; 

 /, dens and mucro of spring (lateral view), X 240. 



support the film surrounding an air-bubble which encloses 

 the insect when submerged. Anurida is found only between 

 tide-marks where it shelters in cracks of the rocks, among 

 seaweeds, or in the empty shells of molluscs. When, as 



