CONTENTS xv 



PAGE 



Class 3. The Myriapoda 239 



Example of the Class — Scolopendra morsitans . . . 239 



Class 4. The Insecta 241 



Example of the Class — Periplaneta americana . . 241 



Class 5. The Arachnida 254 



Example of the Class — Scorpio ..... 254 



SECTION XI 



Phylum Mollusca 



Class 1. The Pelecypoda .... 



Example of the Class — Anodonta cygnea 

 Class 2. The Amphineura 



Example of the Class — Chiton spinosus . 

 Class 3. The Gastropoda .... 



Example of the Class — Helix nemoi-alis . 

 Class 4. The Cephalopoda 



Example of the Class — Nautilus pompilius 



SECTION XII 



264 



265 

 265 

 281 

 281 

 284 

 2S4 

 296 

 298 



Phylum Chordata 310 



Subphylum I. The Adelochorda 311 



Example of the Subphylum — Balanoglossus . . .311 



Subphylum 2. The Urochorda 314 



Example of the Subphylum — Ascidia . . . .314 



Subphylum 3. The Vertebrata 322 



Examples of the Subphylum — Amphioxus, Petromvzon, 



Pisces, etc. ......... 322 



Division A. The Acrania 323 



Example of the Division — Amphioxus lanceolatus . . 323 



Division B. The Craniata 328 



Examples of the Division, the dogfish, lizard, and rabbit . 328 



Class 1. Cyclostomi 360 



Example of the Class — Petromyzon marinus . . . 360 



Class 2. Pisces 365 



Examples of the Class — Sharks, perch, and lung fishes . 365 



