On a new Pseudaxonicl Genus — Dendroyorgia. 63 



The base is wanting. The total height of the colony is 20 cm. and the 

 maximum breadth is 3 - 5 cm. The diameter of the main stem at the 

 base is 9 mm. Near the base it gives rise to two primary branches with 

 diameters of 8 mm. and 7 mm. respectively. The former divides after 

 a distance of 10'5 cm., giving rise to a branch 6 mm. in diameter at its point 

 of origin. The latter branches after a distance of 5 cm.; the diameter of this 

 secondary branch is 6 mm. Slightly beyond this point the main branch 

 has been contorted and curves towards the secondary branch. 



All the branches taper very slightly ; one, however, maintains its original 

 diameter throughout and terminates bluntly in a dome. 



The axis is 5"5 mm. in diameter at the base and tapers to a fine point in 

 the branches ; it is comparatively soft and is easily cut with a knife. The 

 horny part is spongy and the calcareous portion is composed of long smooth 

 or slightly warty irregular spicules, quite unlike those of the ccenenchyma. 

 These are longitudinally disposed. The axis is composed of concentric layers, 

 which, however, are not very distinct ; the outermost of these may be detached 

 in flakes, and the actual arrangement of the spicules is there visible. When 

 boiling down the ccenenchyma in strong caustic potash many of the spicules 

 become detached from the axis, and prolonged boiling of the axis disintegrates 

 the greater part of it. The axis is separated from the ccenenchyma-proper by 

 a thin horny layer in which spicules identical with those of the axis are 

 embedded ; this detaches with the ccenenchyma, but it is undoubtedly a 

 young layer of the axis. 



The ccenenchyma is almost uniformly thick throughout, being, however, 

 slightly thinner towards the base. The proportion of ccenenchyma to axis is 

 markedly different at the various levels (Fig. 3), but in this connection it is 

 noteworthy that increase in thickness towards the base is due not so much to 

 growth in the ccenenchyma as to growth in the axis. The ccenenchyma is 

 comparatively soft, but at the same time densely spiculose. 



Canal system (Fig. 2). — Around the periphery of the axis there is a series 

 of minute longitudinal canals all of the same size. Towards the outside of 

 the ccenenchyma, between the polyps, not internal to them, there are also 

 a number of longitudinal canals, and several are also scattered in the 

 ccenenchyma between these two series. The whole of the ccenenchyma 

 external to the inner series is penetrated by a net-work of transverse canals 

 uniting the various longitudinals. 



The polyps are distributed over the whole of the ccenenchyma (Fig. 3), 

 the actual number at one level being dependent upon the position in the 

 colony. There are no very distinct verrucae, due no doubt to the great 

 thickness of the ccenenchyma; the anthocodiae are withdrawn into the 



