CONTENTS. Vli 

 CHAPTER XXII. 



*AGB 



GENERAL CHARACTERS OF KADI ATA .... 446 



CHAPTER XXIII. 



OF THE CLA&8 OF ECHINODERMATA .... 454 



ORDER I. ECHIMDA ..... 455 



ORDER II. STELLERIDA ..... 464 



ORDER III CRINOIDEA .... 468 



ORDER IV. HOLOTHURIDA .... 472 



CHAPTER XXIV. 



OF THE CLASS OF POLYPLFERA 479 



ORDER I. HELIANTHOIDA .... 481 



ORDER II. ASTEROIDA .... 504 



CHAPTER XXV. 



OF THE CLASS OF HYDROZOA ...... 517 



ORDER I. HYDUOIDA .... 518 



ORDER II. DISCOPHORA .... 529 



ORDER III. CTENOPHORA .... 538 



ORDER IV. SIPHONOPHORA .... 540 



CHAPTER XXVI. 



OF THE PROTOZOA 543 



CLASS I. INFUSORIA ..... 545 



CLASS II. UIIIZOPODA ..... 555 



CLASS III. PORIFERA ..... 559 



APPENDIX. 



ON THE INSTIXCTS OF SOCIAL INSECTS 67 



