XII TABLE OF CONTENTS. 



Spawning season Continued. Pag. 



Compsometra lovCni 37U 



Coccometra nigrollneata 373 



Coccometra hagenli 373 



Psathyrometra fragllls 37., 



I.eptonietra phalangiurn 373 



Hathrometra sarsii 374 



Pentametroerinus tnberculntus . 374 



Pentametroerinus jnponlcus 374 



Pentametrocrinus varlans ^ 374 



Copulation 375 



Passage of the spermatozoa into the receptnculum seminls in Isometra vivipara 375 



Development of the eggs 375 



Growth of the oiicyte 377 



Ripening of the eggs_- 408 



Extrusion of the eggs__ .__ 408 



Egg case 409 



Eggs 410 



Regeneration 410 



Possible extent of regeneration 414 



Influence of different factors on regeneration 416 



Color of regenerating parts 417 



Visceral mass 417 



Details of arm regeneration 424 



Closure of the wound and degeneration of tho cell elements 424 



Rebuilding of the water tube and of (he cmlomtc canal 426 



Dorsal and ventral nervous systems.- 427 



Genital cord 429 



Muscles and ligaments 429 



Skeletal structures 430 



Details of the regeneration of Hie cirri 430 



Embryology and development 431 



Cleavage 433 



Gastrulation 436 



Closure of the Mastopore 439 



Division of the primitive gut into mesenicron, ppriionc:il s^ic. and primary hydroccele , 440 

 Formation of ciliated bands, larval nervous system, and alteration in position of In- 

 ternal organs (60 to S4 hours > 443 



Last period of embryonal development: formation of calcareous skeleton (48 to 120 



hours) 447 



Free swimming larva 450 



Ectoderm 450 



Ectodermal epithelium, ciliated bands, and intermediate areas 450 



Apical pit and nervous system 



Attachment disk and vestibular imagination 454 



Intestinal canal 455 



Coelome and chambered organ 456 



Hydrocoele and parietal canal 



Mesenchyme 



Attachment of larva and its transformation into stalked form 

 Description of larva up to fifth day after escape, from egg membrane- 

 Ectoderm 464 



Vestibule 465 



