164 



BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



EXPLANATION OF PLATES. 



All the figures were drawn with the aid of the camera lucida. Unless otherwise 

 stated, all preparations were fixed in Flemming's stronger chromic-osmic-acetic 

 mixture. 



Owing to defective printing, centrosomes and chromatic granules sometimes 

 appear as rings, instead of solid bodies. 



ABBREVIATIONS. 



Regenerated circular mus- 

 cles. 



Old longitudinal muscles. 



Regenerated longitudinal 

 muscles. 



Polar region ; cytoplasmic 

 fundament. 



Stomodffium. 



Testis. 



Regenerated fibre tract. 



Sheath of nerve cord. 



Cut end of old sheath. 



In Figures 14-16, the * 

 marks tlie point where the 

 old epidermis ends and 

 the regenerated epidermis 

 begins. 



