XII 



Figure 18. A piece of skin farther up the trunk of Duva florida, in which the spicules occur widely separated, magnined. 



— 19. The same spicules, highly magnined. 



— 20. A piece of skin from a branchlet of Duva florida, in which the spicules, very sparing furnished, are extremely small 



and lie remarkably scattered, highly magnified. 



— 21. a, b, c, d) spicules from the body and tentacles of a polyp on Duva florida, highly magnified. 



PL III. 



Figure 1. Duva pellucida, magnified. 



— 2. A polyp from the same animal, magnified: a) series of spicules on the tentacles; b) spicules on the body. 

 Figs. 3, 4, 5. Stellate spicules from the basal part, magnified. 



Figure 6. A very complex stellate spicule, magnified. 



Figs. 7, 8, 9, 10. Spindle and club-shaped spicules on the body, magnined. 



Figure n. Cruciform spicule (Vierling) on the body, magnified. 



— 12. Duva pulcra, magnified. 



— 13. A polyp from the same animal, magnified. 



— 14. Flat spicules from the aboral surface of the tentacles, magnified. 



— 15. Complex stellate spicule from the basal part, magnified, 



Figs. 16, 17. A simple and a complex stellate spicule from the lower part of the trunk, magnined. 

 Figure 18. a, b, c) simple stellate spicules from the basal part, magnified. 

 Figs. 19, 20. Cruciform spicules from the basal part, magnified. 



— 21, a, b) 22. Spicules from the median and anterior parts of the body, magnified. 



— 23, 24. Furcate and cruciform spicules from the posterior part of the body, magnified. 

 Figure 25. Clavularia arctica, magnified. 



— 26. A polyp, magnified: a) the margin extending along the upper portion of the posterior part of the body (calyx); 



b) anterior part of body. 



Figs. 27, 28, 29. Spicules from the basal part, cruciform and spindleshaped, magnified. 



— 30, 31. Spindleshaped and well developed cruciform spicules from the posterior part of the body, magnified. 

 Figure 32. A cruciform spicule from the anterior part of the body, magnified. 



Figs. 33, 34, 35. Spicules from the tentacles, in form of disks and but little developed crosses, magnified. 



Pl. IV. 



Figure 1. Sarcophyton purpureum, natural size: a) basal part; b) zooids. 



— 2. Disk with its polyps, natural size. 



— 3. Polyp, surrounded by zooids, magnified. 



— 4. Transverse section of the skin, magnified 750 times, drawn by Camera lucida: a) ectodermic cells ; b) hyaline, con- 



nective tissue; c) nutritive canals with epithel; d) a smaller do.; e) spicule; f) corpuscle of connective tissue. 



— 5. Transverce section of a piece of the disk between two polyps, magnified: a) prolongations of connective tissue, in 



which spicules are seen; b) the gastral cavities of the zooids, in which egg-capsules and partly -the oesophagus of 

 the zooid are seen; c) and d) the two mesenterial-nlaments. 



— 6. Entodermic cells, magnified 750 times, drawn by Camera lucida. 



— 7. Spicules on the oesophagus, magnified. 



8. Longitudinal section of the zoanthodeme, magnified: a) oesophagus of the polyp; b) the long gastral filament; 



c) the short gastral filaments ; d) canal, in which the gastral cavity of the zooid is continued ; e) the zooids with 

 their generative organ es; f) the canal-system. 



Figs. 9, 10 a, b) 11. Spicules in the connective tissue of the gastral filaments, magnified. 



Figure 12. Transverse section of the upper part of a zooid, surrounded by a circle of spicules, magnified: a) Spicules; b) the 

 long septa; c) the short do.; d) oesophagus. 

 14. Spicules surrounding the zooid, magnified. 

 16, 17. Spicules from the basal part, magnified. 



Spicule from the uppermost part of the stem and in the coenenchym. 



A piece of a tentacle, magnified: a) spicules on the aboral surface; b) spicules on the sides; c) spicules on the 

 pinnules. 

 Figs. 20 — 25. Spicules on tentacles and polyp-body. 



Figs. 



13, 



— 



15, 



Figure 



18. 



— 



19. 



