XI 



PHYLUM ARTHROPOD A 



007 



CLASS II.-ONYCHOPHORA. 



The class Onychophora comprises only the aberrant arthropod 

 genus Peripatus, with several sub-genera, which differs very widely 

 in certain important features of its organisation from all the rest 

 of the Arthropoda, and in some respects enables us to bridge over 



FIG. 479. Peripatus capensis, lateral view. (From Balfour.) 



the interval between the latter and some of the lower phyla, 

 more particularly the Annulata. 



General external features. --Peripatus (Fig. 479) is a cater- 

 pillar-like animal of approximately cylindrical form, and not divided 

 into segments : it has a fairly well-marked head, and a series (14 

 42, according to the species) of pairs of short stumpy appendages. 



FIG. 480. Ventral view of head of Peripatus capensis, with antenna 1 , jaws, oral papilla 1 , 



and first pair of legs. (After Balfour.) 



The integument is thrown into a number of fine, transverse 

 wrinkles, and is beset with numerous conical papilla 1 , each 

 capped with a little chitinous spine. The head (Fig. 480) bears 

 a pair of antenna, a pair of eyes, a pair of jaws, and a pair of 

 short processes known as the oral papillcr. The antennaB are made 



