26 4 



ZOOLOGY 



of Peripatus 



of being in pairs, one on each side 

 of each segment. Since the form of 

 the tracheae and other structural 

 features in the Peripatus are very 

 ' unlike those of the typical tra- 

 cheate arthropods, such as the 

 insects, it is evident that we can 

 regard the Prototracheata only as 

 a relatively primitive type, not in 

 any sense as truly ancestral. It 

 is a branch from an early stock 

 which came off very long ago, and 

 has been modified in its own way, 

 which is not the way of the-insects 

 Distribution or spiders. At the present time 

 the species are w idely scattered 



and generally rare, as is usually 

 the case with an ancient and 

 waning stock. When alive, the 

 Peripatus is a very handsome 

 animal, with a soft, velvety skin, 

 which in some species is very 

 beautifully colored with subdued 

 shades of reddish or greenish. 

 The numerous pairs of soft legs 

 remind one of the abdominal legs 

 of a caterpillar, while the soft, 

 flexible antennae are not unlike the 

 tentacles of a snail or slug. The 

 form figured was found in South 

 Africa. No kind of Peripatus is 



FIG. 77. Peripatus (Peripatopsis) capensis, X 3 ; 

 viewed from the dorsal surface. The largest speci- 

 men recorded was 65 mm. long. 



After drawing by Miss Balfour 



