470 horneeidyE. 



short and truncate. Zocecia crowded, distinct, generally 

 a good deal produced, surface punctate ; dorsal surface 

 granular, the extremities of the branches with a rib-like 

 elevation down the centre. Ooecia elongate, placed in 

 the axils of the branches, partly on the front and 

 partly on the back of the zoarium (chiefly placed on the 

 back, but bent round the side of the branch towards 

 the front), smooth, closely punctate, with a slight longi- 

 tudinal costa ; orifice bilabiate, situated near the top. 



Colour, when fresh, white with a violet tinge. 



Height from ^ to | inch. 



//. rioLACEA differs from the preceding species in the 

 following points : — The front surface is not fibro-reticulatc 

 as in the last, the cells are somewhat longer, much more 

 crowded, and more j)roduced; the dorsal surface is gra- 

 nular, and on this side the branches are ribbed centrally 

 towards the extremities ; the ooecium is narrow and elon- 

 gate, with a bilabiate orifice near the top, whereas that of 

 H. lichenoides is ovate or suborbicular, much elevated, 

 with a lateral and tubular aperture. The colour of the 

 zoarium is also distinctive. The ooecium in the specimen 

 from which the figure was taken (Plate LXII. fig. 3) 

 was invested for some distance above the base by a thick 

 calcareous crust, apparently continuous with the external 

 layer of the zoarium. This crust extended round the 

 sides of the ovicell, leaving the upper surface free. 



I have not included amongst the synonyms the Hornera 

 violacea, forma proboscina, Smitt, as, judging from the 

 figure of the ooecium given in the Scandinavian Catalogue, 

 it must be specifically distinct. The ovicell in this form 

 is placed on the front of the branches, is round and flat- 

 tened, and covered with large pores arranged in radiating 

 rows. 



Habitat. On corals &c., in deep water. 



