xu 



CONTENTS. 



Chapter XVII. BRACHIOPODA— co7i<in«erf. 

 IV. General considerations 

 Literature 

 Appendix — General considerations on 

 Rhabdoplenra and Cephalodiscns 

 Literature 



the Mollusooida 



K. HhlDER 



Chapter XVIIL ENTOPROCTA. By 

 Embryonic development and larva 

 Metamorphosis 

 Asexual reproduction 

 General considerations 

 Literature 



Chapter XIX. CRUSTACEA. By K. Heideii 



Systematic 

 I. Development of the embryo 



1. Oviposition, care of the brood 



2. Cleavage and formation of the blastoderm 



Vitelline membrane 



Types of cleavage 



Blastodermic cuticle, larval integument 



Paracopulation . 



3. Formation of the germ-layers 



A. Copepoda 

 £. Phyllopoda . 

 C. Cirripedia 



D. Decapoda 



E. Scliizopoda . 



F. Arthrostraca and Cumaeea 



G. General considerations 



Types of development of the enteron 

 Formation of the mesoderm . 



4. Development of the external form of the body 



A. Entomostraca 



B. Arthrostraca and Cumaeea 



Dorsal organ 

 C Leptostraca, Schizopoda, and Deca|)oda 



5. Formation of the organs 



A. External integument . 



B. Endoskcleton 



C. Nervous sj'stem 



Development of the brain 



Primary segmentation of the ce[)halic r 



D. Sensory organs 



Develo])meut of the comj)Ound eye 



Development of the auditory organ 



K Gills 



F. Intestinal canal 



Entomostraca 



Decapoda 



Arthrostraca 



G. Heart 



