THE ORDER AMONG ANIMAL TYPES 



113 



portant respects resembles the annelids and is of interest because 

 it may represent the transitional type between the two phyla. No 



ARTHROPOD A 



FIG. 58 ONYCHOPHORA - PERIPATVS 





FIG. 59 UYRIAPODA- MILLIPEDE 



FIG. 57. CRUSTACEA -CRAYFISH 



FIG. 60. INSECTA - HOUSE FLY 



FIG. 61 ARA CHNIDA - SPIDER 



Figs. 57, 58, 59, 60, and 61. — Representatives of the five classes of Arthropoda. 

 The arthropod characters are less conspicuous in the figure of Peripatus (Fig. 58) 

 than in the others; the jointed structure of the appendages can be distinguished. 

 (Fig. 58 after Sedgwick.) 



examples are found in North America. Peripatus is a South Amer- 

 ican representative of the class. 



