4 AN INTRODUCTION TO ENTOMOLOGY 



FF. Larva with two pairs of legs, adult without 



legs PENTASTOMIDA 



BBB. With one pair, and only one, of feeler-like antennae. 



Respiration aerial. 



C. With more than three pairs of legs, and without wings. 

 D, With two pairs of legs on some of the body-segments. 



DIPLOPODA 

 D D . With only one pair of legs on each segment of the body . 



E. Antennae branched PAUROPODA 



EE. Antennae not branched. 



F. Head without a Y-shaped epicranial suture. 

 Tarsi of legs with a single claw each. Opening of 

 the reproductive organs near the caudal end of 



the body CHILOPODA 



FF. Head with a Y-shaped epicranial suture, as in 

 insects. Tarsi of legs with two claws each. 

 Opening of the reproductive organs near the head. 



SYMPHYLA 



CC. With only three .pairs of legs, and usually with wings in 

 the adult state HEXAPODA 



CLASS ONYCHOPHORA 



The genus Peripatus of authors 



The members of this class are air-breathing animals, with a nearly 

 cylindrical, unsegmented body, which is furnished with many pairs of 

 unjointed legs. The reproductive organs open near the hind end of the body. 

 The class Onychophora occupies the position of a connecting link 

 between the Arthropoda and the phylum Annulata or worms; and is 

 therefore of the highest interest to students of systematic zoology. 

 All known members of this class have been included until recently in a 

 single genus Peripatus; but now the fifty or more known species are 

 distributed among nearly a dozen genera. 



The body 

 (Fig. 5) is nearly 

 cylindrical, cat- 

 erpillar - like in 

 form, but is un- 

 segmented ex- 

 ternally. It is 

 Fig. 5 .Peripaloides nova-zealandica. furnished with 



many pairs cf legs, the number of which varies in different species. 

 The legs have a ringed appearance, but are not distinctly jointed: 



