Part II Systematic List. 



Order THYSANURA. 



This order contains the "spring-tails" and "bristle-tails," which are 

 small or minute, soft-bodied creatures without wings and no obvious 

 transformations. The mouth parts are feebly developed, without obvious 

 mandibles, and they are. as a rule, feeders upon the products of decay, 

 though some of the larger forms are able to attack dry and hard sub- 

 stances by scraping uie surface. They are 

 among the most primitive of existing insects, 

 a few of them closely resembling the early 

 stages of "Myriapods," while in others the 

 tracheal system is so feebly developed that 

 respiration seems a function of the entire 

 skin surface. Such insects can live in moist 

 places only, and die as soon as they are ex- 

 posed to drying out. 



In this order Mr. R. P. Dow has kindly fur- 

 nished the list, including such species as are 

 so generally distributed that their occur- 

 rence in New Jersey is practically certain. 

 There have been no actual collections. 



Sub=order CINURA. 



The long anal appendages which give 

 these insects the name "bristle tails" are 

 many-jointed and extend straight out. 

 None of the species are jumpers. 



LEPISMA Linn. 



L. saccharina Linn. Occurs in households 

 all over the world and generally in cel- 

 lars or damp places. Is fond of moist 

 sugar, and will feed also on starchy 

 materials. 



L. quadriseriata Pack. Similar in habit to 

 the preceding, but a native insect, more 

 common southwardly. 



Fig. i. Silver-fish, Lepisma sp. ; 

 very much enlarged. 



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