CONTENTS xvii 



_^ FAGE 



-I HYLVM XuTimopniiA—ainiiniud. 



Class IV. Insecta . . 619 



1. Example of the Class — Pcriplaneta urientalis or P. aiiii'vii-unii 619 



2. Distincti\"e Chaiacters and Classiticatiou , 631 

 Systematic Position of the Example 636 



3. General Organisation . . 636 

 Class A' Arachnida 653 



1. Example of the Class — Enscvipiu ur Btithu^ . . 663 



2. Distinctive Characters and Classification 660 



3. General Oryanisation ... ... 662 



Appendix to the Arachnida — the Fiji-iuxjimiihi. Ijinijindtdidii, 



and Tanlujnid<i . .... 673 



Relations of the Air-breathing Arthropoda . 676 



SECTION XII 



Phylum Molllsua . .... 680 



Class I. Pelecypoda . . . . • 680 



1. Example of the Class— ^(tyrfofifd and fu/o . . . 680 



2. Distinctive Characters and Classification 694 

 Systematic Position of the Examyjles . 696 ■ 



3. General Organisation . 696 

 Class II. Amphineura 712 



1. Distinctive Characters and Classitication . 712 



2. General Organisation . . . . 713 

 Class III. Gastropoda . . 721 



1. Example of the Class — Triton luidiferux 721 



2. Distinctive Characters and Classification . 732 

 Systematic Position of the Example . 734 



3. General Organisation . . 735 

 Appendix to the Gastropoda . 756 



A. Class Scaphoda . 756 



B. Rhodope .758 

 Class V. Cephalopoda 769 



1. Examples of the Class . . 759 

 i. Sepia . . . 769 



ii. NaiiUlus poinpdiiiji . . 776 



2. Distinctive Characters and Classification . 789 

 Systematic Position of the Examples . . 790 



3. General Organisation .... . . . 790 



General Remarks on the Mollusca , . 804 



VOL. I 



