CONTENTS. XV 



of the Trilobita General structure of a Trilobite Appendages 

 of Trilobites Systematic position of Trilobites Distribu- 

 tionof Trilobites in past time Leading families of the Trilobita 

 Characters and divisions of the Merostomata Characters and 

 . distribution in time of the Eurypterida Characters and dis- 

 tribution in time of the Xiphosura, 341-386 



CHAPTER XIX. 



Characters of the Malacostraca Characters of the Edriophthalmata 

 Characters and distribution in time of the Amphipoda 

 Characters and distribution in time of the Isopoda Characters 

 of the Podophthalmata Characters and distribution of the 

 Stomapoda Characters and distribution of the Decapoda 

 Macrura Anomura Brachyura Literature of Crustacea, 387-397 



CHAPTER XX. 



Characters of the Arachnida General distribution of the Arachnida 

 in time Characters and distribution of the Scorpionidse Cha- 

 racters and distribution of the Araneida Characters and dis- 

 tribution of the Myriapoda Characters and distribution in 

 time of the Insecta Literature of Arachnida, Myriapoda, and 

 Insecta, 398-409 



CHAPTER XXI. 



General characters of the Moll usca General characters of the shell 

 of the Molluscs General distribution of the Mollusca in time 

 Divisions of the Mollusca Characters of the Polyzoa Struc- 

 ture of the polypides and colonies of the Polyzoa Divisions of 

 the Polyzoa Distribution of the Polyzoa in time Chief fam- 

 ilies of the Polyzoa and their range in time, . . . 410-434 



CHAPTER XXII. 



General characters of the Brachiopoda Structure of the shell of the 

 Brachiopods Oral processes and their supports Divisions of 

 the Brachiopods-: General distribution of the Brachiopoda in 

 time Characters, distribution in time, and leading genera of 

 the Terebratulidae Thecidiidse Spiriferidse Koninckinidse 

 Rhynchonellidae Strophomenidse Productidse Craniadse 

 Discinidse LingulidjB Trimerellidse, . . . . 435-463 



