55 



CHAPTER IV. 



COLLEMBOLA. 



General Description. 



In tlie CoLLEMBOLA, as in true insects, tlie body is 

 divided into three distinct sections — the head, thorax, 

 and abdomen. The head bears the antennae, the eyes, 

 and the mouth-organs ; to the thorax are attached the 

 three pairs of legs; to the abdomen, the sucker, the 

 catch, and the saltatorial appendage, or spring. 



The skin is clothed with hairs, and in several 

 genera with scales. In addition to the ordinary hairs, 

 which are of various lengths, some genera bear others 

 of peculiar forms ; for instance, Degeeria has club-shaped 

 hairs (PI. LXV, fig. 8), and others which more or less 

 resemble a bow (PI. LXV, fig. 7), not only in the 

 general form, but in having a notch at the end, closely 

 imitating that by means of which the bowstring is 

 attached. Several species also have on their feet, and 

 in some cases, as in Smynthurus fuscus, on the salta- 

 torial appendage, one or more tenent hairs, that is to 

 say, hairs which are swollen at their extremity, and 

 which assist the animal to retain its hold on slippery 

 surfaces. 



The scales are of very various forms and sizes, even 

 in the same species ; they are generally colourless, but 

 in some species, especially in the genus Lepidocyrtus, 

 are beautifully iridescent. While, however, the scales 

 do not generally offer specific characters either in their 

 form or magnitude, the structure of the scale is often 

 very characteristic. I will not, however, enlarge on 

 this subject, as I shall hope to append a special 



