X CONTENTS 



CHAPTER IV. 

 The Leech. Hwudo meddcmaUs. 



PAOK 



External characters — Dissection — Examination of transverse sec- 

 tions 86 



CHAPTER V. 

 The Earthworm. Lvmbricua terrestris. 



External characters — Dissection — Examination of transverse sec- 

 tions 55 



CHAPTER VI. 

 The Freshwater Mussel. Anodonta cygnea. 



The shell — Dissection of the mussel — Examination of transverse 



sections 75 



CHAPTER VII. 

 The Edible Snail. SeUx pomaUa. 



External characters — Dissection of the snail 102 



CHAPTER VIII. 

 The Crayfish. Astacus fiuviatiUs. 



External characters — Dissection — The arteries as seen in an 



injected specimen 124 



CHAPTER IX. 



The Cockroach. Peripla/neta americoMa. 



Habits — External characters — Dissection 152 



