CONTENTS. XV 



CHAPTER XIX. CRUSTACEA- continued. PAGE 



G. Anomnra . . . ... 285 



Zoaea and Metazoaea of the Anoniura . . . 286 



Larva of Porcellana (Lonchophorus) . . . 289 



Larvae of the Hippidae . ... 290 



H. Brachyura . . . ... 290 



Zoaea of the Brachyura . ... 291 



Metazoaea . . ... 293 



Megalopa . . ... 294 



Abbreviated development of some Brachyura . . 296 



11. Metamorphosis of the Stomatopoda . ... 297 



Erichthoidina stage . . ... 297 



Erich thus stage . . . ... 301 



Alima stage . . . ... 301 



Connection of the larval forms with definite genera . . 303 



12. Metamorphosis of the Ciunacea . ... 303 



13. Metamorphosis of the Anisopoda . ... 304 



14. Metamorphosis of the Isopoda . ... 304 



Larvae of the Anceidae . . ... 305 



Larvae of the Bopyridae . . ... 306 



Larvae of the Entoniscidae . ... 307 



15. Metamorphosis of the Amphipoda . ... 309 



16. General considerations regarding the development of the 



Crustacea . . . ... 309 



Phylogenetic significance of the Zoaea . . . 310 



Phylogenetic significance of the Nauplius . . . 313 



Hypothetical derivation of the Crustacea from the Annelida 313 

 Relations of the Protostraca to the Palaeostraca, Pantopoda, 



and Peripatus . . . . . 315 



Characteristics of the primitive Phyllopoda . . . 316 



Relationships of the Entomostraca . ... 317 



Relationships of the Malacostraca . ... 318 



Significance of Nebalia . . ... 318 



Literature of the metamorphoses of the Crustacea . . .319 



CHAPTER XX. PALAEOSTRACA. By K. HEIDER . . 332 



General considerations regarding the Palaeostraca . . . 332 



I. Metamorphosis of the Trilobita . . ... 334 



II. Development of the Xiphosura . . ... 340 



1. Oviposition, cleavage, and formation of the germ-layers in 



Limulus . . . ... 340 



2. Development of the external form of the body . . . 343 



Trilobite stage of Limulus . ... 347 



3. Formation of the organs . . ... 348 



A. Nervous system and sensory organs . . . 348 



B. Alimentary canal . . ... 352 



C. Formation of the mesoderm . ... 353 

 D. Respiratory organs . , ... 355 



4. General considerations regarding the Palaeostraca . . 356 



Relations of the Palaeostraca to the Arachnida . . 356 



Literature of the Palaeostraca 360 



