Muricella rubra, Thomson, var. robusta, ii. 



Two young colonies represent this new variety. 



The more complete is 90 mm. in height and 40 mm. in maximum breadth ; 

 it is of a pur})lish-red colour with white polyps. The branching is sparse and is 

 confined to one plane ; the branches are more distant than in M. rubra and arise 

 more regularly. The verructe are alternate and are considerably elongated in 

 the direction of the axis, being also flattened in the plane of ramification. The 

 C(_enenchyma is thin and has a very even surface, the larger s})icules being em- 

 bedded among the smaller but not projecting beyond the surface. The polyps 

 are white, and when imperfectly contracted stand out in strong contrast ; they 

 are densely covered with small transparent spicules arranged transversely. On 

 the aboral surface of the tentacles there are triangular groups each consisting 

 of a large number of spindles with a slightly " en chevron " arrangement. The 

 spicules of the coenenchyma show the same features as to size and arrangement 

 as in M. rubra, but here they are much larger. 



The following are some of the measurements length and breadth in milli- 

 metres : — 



{a) Coenenchyma, 1-8 x 02 ; 1 x 0-15 ; OSo x Ol. 



{b) Verrucfe, 0-5 x 005 ; 0-45 x 0-05. 



{e) Polyp, 0-25 x 002 ; 02 x 0-02. 



This specimen shows a marked resemblance to M. rubra, but as it differs in 

 the following respects we have named it as a new and distinct variety, viz., 

 robusta, n. : — 



(1) The branching is sparse and the branches are more regular and distant. 



(2) The verrucKi are more strictly alternate, more flattened in the plane of 

 ramification, and more elongated in the direction of the axis. 



(3) There is a greater abundance of spicules on the polyps, and the tenta- 

 cular operculum is better developed. 



(4) The spicules are larger in proportion to the size of the colony. 

 Localities : Andamans, and Station 78 off Ganjam Coast, 18 fathoms. 



A small bright red colony with white anthocodi?e in the Wood-Mason 

 Collection seems referable to this species. It is more bushy than the general 

 type and diverges slightly from the robusta variety, being intermediate in 

 several characters. 



Muricella arborea, n. sp. 

 Plate III. figs. 1 and 5; Plate VIII. fig. 18. 



This new species is represented by a beautiful robust colony 19 cm. in 

 height and 11 cm. in breadth. The mode of branching differs from other 

 species of Muricella and is by no means obvious. The larger branches arise 



