ON THE LIFE-fllSTOET OF PBDIOELLINA. 171 



Fig. 5.— Horizontal section, at an early stage in the metamorphosis, passing 

 through the tip of the epistome, the lateral folds and oral grooves, and the 

 apex of the anal cone. 



Figs. 6 and 7.— Two sections of a considerably older individual, passing 

 respectively in the planes £ L and I J in Fig. 16. 



Figs. 8 and 9. — Two sections of an individual of the age of Fig. 16, passing 

 in an obliquely longitudinal direction. Fig. 8 cuts the mouth and one of the 

 lateral portions of the permanent vestibule. Fig. 9 passing through the rectum 

 and the degenerating vestibule of the stalk. In another section of the same 

 series the two parts of the vestibule are continuous, exactly as in the diagram, 

 Fig. 16. 



Fig. 10. — Median longitudinal section of an advanced, but still solitary, 

 individual. 



Fig. 11. — Horizontal section (in the plane G H in Fig. 10) through a 

 similar specimen. 



Fig. 12. — Section of an individual of the age of Figs. 8 and 9, passing in 

 the plane B F in the latter figure. 



Fig. 13. — Median longitudinal section through the stalk of a solitary 

 individual with commencing primary stolon. The arrow indicates the position 

 of the oral side of the calyx. 



Fig. 14. — Obliquely transverse section of a young bud, developed at the 

 growing point. 



PLATE XVII. 



Fig. 15. — Young bud of Loxosoma, from the ventral side. Copied from 

 0. Schmidt, 'Arch. f. mik. Anat.,' Bd. xii, 1876, PI. Ill, fig. 17. 



Fig. 16. — Diagrammatic longitudinal section of a metamorphosing Pedi- 

 cellina at the stage of Figs. 8, 9, &c. 



Figs. 17 — 19. — Diagrams illustrating the supposed morphological nature of 

 the metamorphosis of the Entoprocta. A full explanation is given in the 

 text. 



