268 



ZOOLOGY 



Springtails 



Thysanura 

 or " silver 

 fish" 



and used as organs of touch, in the absence of the an- 

 tennae. The first three abdominal segments have short 



appendages. These singular little ani- 

 mals were first made known by the 

 Italian entomologist, Silvestri, in 1907, 

 but have since been found in many 

 countries. They combine primitive 

 with specialized characters. 



FIG. 80. A springtail 

 (Entomobrya) ; greatly 

 magnified. 



Order Collembola 



Small, wingless terrestrial insects, 

 without metamorphosis. The an- 

 tennae are well developed, but have 

 few joints. A forked appendage (fur- 

 cula) beneath the abdomen enables the 

 From Bulletin 6 7 , u. s. msect to leap - in one group this is 



National Museum 



absent. The body is sometimes 

 clothed with scales. These small 

 creatures, known as "springtails," may 



be found under rocks. One kind 



occurs on snow in the winter. 



Order Thysanura 



Wingless terrestrial insects with 

 slender antennae and six legs. 

 They do not leap, and are gener- 

 ally much larger than the Collem- 

 bola, though of no great size. A 

 common form, found in houses, is 

 somewhat carrot-shaped, with sil- 

 very, glistening scales, and is pop- 

 ularly known as the "silver "fish." 

 It is about one third of an inch 

 long, and has three long tails. 



From Bulletin 67, U. S 

 National Museum 



FIG. 81. A "silver fish" 

 (Lepisma) . 



