346 DE. S. J. HICKSON — EBVISIOX OF THE 



32. VerrilLj a. E.- — Notes ou Radiata. Trans. Connecticut Acad. vol. i. 1868, pt. 2, no. 6, p. 455. 



33. Verrill, a. E. — Critical Eemarks on the Halcj'onoid Polyps in the Museum of Yale College. 



Am. J. Sci. 1868. 



34. Verrill, a. E. — Radiata from the Coast of North Carolina. Am. J. Sci. 1872. 



35. ViGuiER, C. — Un nouveau type d'Authozoaire [Fascicularia edwardsi). Arch. Zool. Exp6r, 



2^ serie, vol. vi. 



EXPLANATION OF THE PLATES. 



PLATE XLV. 



Stereosoma celebense, p. 337. 



PLATE XLVI. 



Clavularia garcim, p. 341. 



PLATE XLVII. 



Clavularia reptans, p. 342. 



PLATE XLVIII. 



Clavularia celebensis, p. 342. 



PLATE XLIX. 

 Clavularia viridis, p. 343. 



PLATE L. 



Structure of Stereosoma and Clavularia. 



Fig. L Transverse section through a portion of the body-wall and one mesentery of 

 Stereosoma celehense, showing the thick vacuolated ectoderm, consisting of 

 an outer layer of cells and a subjacent dense homogeneous substance con- 

 taining a number of isolated cells, rods of cells, and cell islets {EctJ), as weU 

 as the vacuoles or lacunae. The mesogloea is sharply defined and is not 

 vacuolated. A considerable number of zooxanthellse may be seen adhering 

 to the endoderm. 



Fig. 2. Outline drawing of a transverse section through Stereosoma celehense in the 

 region of the stomodaeum, showing the small but prominent muscular ridges 

 and the siphonoglyphe. 



Fig. 3. A small specimen of Clavularia australiensis. Variety A. 



Fig. 4. Two forms of the spicules of Clavularia jiustraliensis, Variety A. 



