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CONTENTS. 



Chapter XXXI. SOLENOCONCHA. By E. Korschelt 



1. Cleavage and formation of the germ-layers 



2. The development of the form of the larva 



3. The transformation of the larva into the adult 

 Literature ........ 



Chapter XXXII. GASTROPODA. By E. Korschelt 



1. Oviposition and character of the egg-capsules and the egg 



2. Cleavage and formation of the germ-layers 



3. The formation of the germ-layers . 



The mesoderm ..... 



4. The rise of the larva and its relation to the adult form 



The ontogeny of Patella .... 



The Trochophore stage .... 



The Veliger stage ..... 



The development of Paludina 



The primitive kidneys ..... 



The shape and transformation of the blastopore 



Considerations relating to the asymmetry of the Gastropoda 



5. The development of the external form of the body in the 



different divisions of the Gastropoda 



A. Prosobranchia . 



B. Heteropoda 



C. Opisthobranchia 



D. Pteropoda 



Thecosomata 

 Gymnosomata 

 K. Pulmonata 



The ontogeny of the 

 Pulmonates . 

 (». The formation of the organs 

 -4. The shell . 



B. The nervous system . 



C. The sensory organs . 



The eyes 

 The otocysts . 

 The osphradium . 



D. The pedal glands 



E. The alimentary canal 



F. The gills . 



G. The differentiation of the mesoderm-rudiment, the 



development of the body-cavity, the nephridial and 

 circulatory systems 



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terrestrial 



II 

 Literature 



The genital organs 



Chapter XXXIII. CEPHALOPODA. By E. Korschelt 



1. Oviposition and the constitution of the egg . 



2. Cleavage and formation of the germ-layers 



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