The mesenterial Filaments of the Alcyonaria. 27 



Fig. 4. Similar view of a much older, nearly half-grown bud of the same species. 

 x25. 



Fig. 5. Longitudinal section through a yoiing sexual bud of Kophnbelemnoii from 

 the lower part of the polyp-bearing region. The Oesophagus is obliquely 

 cut so that its communication with the exterior does not appear (for this 

 see figs. 10. 13). The whole length ofoneofthe dorsal filaments, d.f., 

 is shown, extending downwards into the canal-system. The latter com- 

 municates at a, a, with the main longitudinal canals, and at h with the 

 next younger polyp below. The upper part of the section is at the left 

 band, x SO. 



Piate 2. 



Fig. 0. Cross-section through the dorsal filament of Gorgonia verrucosa, x 400. 



Fig. T. Similar section through the dorsal filament of a young sexual polyp of 

 Funiculina. X 400. 



Fig. 8. Similar section through the dorsal filament of Paralcyonium. x 400. 



Fig. 9. Similar section through the dorsal filament of a zooid oi Kophohelemnon. 

 X400. 



Fig. 10. Longitudinal section through a bud oi Alcyonimn palmatam slightly older 

 than fig. 3. To the right — which is the side turned towards the end of 

 the branch — the cavity of the bud overlies an older polyp, P, and at the 

 left or lower end it communicates with the canal-system, x 80. 



Fig. 1 1 . More highly magnified view of the rudiment of the ventral filament shown 

 at e.f. in fig. 10., showing its connection with the ventral wall of the 

 Oesophagus v.w. , at in. At ü is a vacuolo containìng a foreign body. 

 X 400. 



Fig. 12. Cross-section of one of the entodermic filaments of Para/cyonn»». At d 

 ìs a diatom embedded in the filament. ne. nettle-capsules. x 400. 



Fig. 13. Longitudinal section through three hndsof Fimtculin a. In the youngest, 

 A, the dorsal filaments, d.f., are quite riidimentary and the entodermic 

 filaments bave not yet appeared. In B the dorsal filaments bave attained 

 a considerable length, and a slight accumulation of entoderm-cells at e.f. 

 probably marks the beginning of one of the ventral filaments. In C 

 the dorsal filaments are very long and the entodermic filaments, e.f, are 

 distinctly visible. At « are vacuoles containìng food-particles. x 130. 



Fig. 14. Diagram constructed from a figure by Kölliker, of six polyps from the 

 leaf of Halisceptrum, showing the dorsal filaments. 



Fig. 15. Semi-diagrammatìc figure of a portion of a branch oi Alcyonium palma- 

 tum ; p. youug buds, P. older polyps. The long axis of the figures cor- 

 responds with that of the branch. The dorsal septa and filaments are 

 diagrammatically represented at d.f. x 3. 



Fig. 16. Diagram of a cross-section of a simple eight-rayed polyp to show its 

 relations whith an animai possessing stomodaeum , proctodaeum and a 

 segmented coelom. In the centre is the elongated Oesophagus with the 

 form it possesses in Alcyonium , showing the dorsal [d.d.) and ventral 

 [cd.) divisìons. d.-p. »glandulär« portion of filament, e.])., non-glandu- 

 lar portion (cf.Fig. 12). The dotted lines represent the supposed union of 

 the filaments and the Splitting of the Oesophagus into two distinct tubes. 



