508 THE STOLOXIFERA AND ALCYONACEA IN NEW BRITAIN, ETC. 



Fig. 8. Alcyonium macropodium, n. sp. Colony x 1. 



Fig. 9. Alcyoiiium macropodium. One polyp contracted showing valve-like folds (v.) which 

 can be drawn over the folded tentacles. 



Fig. 10. Spicules of Alcyonium macropodium. 



PLATE LI. 



Fig. 11. Polyp head of Spongodes rakaiyae, n. sp., to show the arrangement of the 

 spicules. 



Fig. 12. A diagrammatic transverse section of a branch of Telesto arthiiri. In the centre 

 are four large coelenteric cavities {p. c), the tubes of polyps borne close to the part of the 

 branch from which the section is taken. 



The four smaller coelenteric cavities somewhat to the outside of these are polyp tubes 

 cut nearer to their point of origin ; the polyp tubes become smaller as they are traced 

 down the branch. The dorsal mesenteries {d. m. f.) with their filaments extend the whole 

 length of the polyp tubes, and traces of some of the lateral and ventral mesenteries are 

 usually seen in section. The dorsal mesenteries are on the side of the tube nearest to the 

 axis. 



Ova {ov.) are found attaclied to some of the lateral mesenteries. 



The mesogloea between the polyp tubes contains numerous small endoderm-canals, but 

 these do not extend to the surface of the branch (c. c). 



Two pohps are shown cut across. One {t. s.) is a transverse section of the polyp just 

 below the stomodaeum, sliowing the large bundles of muscle fibres on the mesenteries which 

 however extend only for a very short distance down the tube, and the mesenteries become 

 mere little projecting lumps of mesogloea covered by a thin layer of endoderm cells con- 

 tinuous with the layer lining the polyp tube. 



The other polyp (/. *■.) is cut longitudinally and shows two retracted tentacles and the 

 stomodaeum in longitudinal section. 



The large cavities near the edge of the section represent the ca^-ities occupied in nature 

 by the spicules. 



Fig. 13. A retracted polyp of Clavularia viridis as seen when cut longitudinally in 

 half. V. m. /., the ventro-lateral mesenterial filaments commencing some distance from the 

 stomodaeum ; d. m. f., the dorsal mesenterial filaments extending the whole distance from the 

 stomodaeum to the base; </., the gonads; t., tentacle; St., Stomodaeum. 



Fig. 14. A portion of a dorsal mesentery of a polyp of Clavularia viridis enlarged to 

 show the form of the dorsal mesenterial filament [d. m. /.). 



