LITIIOBIUS 



101 



when disturbed, roll up spirally. P. canadensis, of the northern 

 United States, is deep brown, with hairy antcnnte (Fig. 103). 

 These myriapods are destructive to agri- 

 culture, especially to cabbage and straw- 

 berries. 



Two genera of myriapods which stand 

 somewhat isolated deserve a passing 

 notice. Pau'ropus ^ and allied genera 

 include a few animals, about 1 millimetre 

 long, found on the moist loam of woods. 

 They are intermediate between chilopods 

 and diplopods, inasmuch as they have only 

 one pair of legs to a segment, but the 

 segments tend to unite in pairs. Scol'open- 

 drella ^ is a small, white species, having 

 very large antennae and a pair of back- 

 ward-directed stylets. The mouth parts are very much like 

 those of the lowest insects, so that Scolopendrella bridges the 

 gap between myriapods and true insects. The presence of 

 these connecting species incUcates that the groujos that are now 

 separated are of common origin. 



Fig. 103. — Pohjdcsmus 

 canadensis ( = P. scrra- 

 tiis). :■ 1.5. Photo, by 

 W. H. G. P. 



Fig. 104. — Peripatu.s, the air-breathing, wormhke animal that bridges the 

 gap between Myriapods and worms. 



Finally, the myriapods seem to be connected with the 

 worms by a pecuhar air-breathing tropical animal known 

 as Perip'atus (Fig. 104). In many details of structure this 

 resembles a polychaetous worm (Chapter XI). 



'^ pauros, small; pous, foot. ^ Diminutive of Scolopendra. 



