356 Proceedings of the Roi/al Irish Academi/. 



The total height of the colouy is 31 cm. ; it consists of a main stem 

 30 cm. in height, from which four branches arise, all ou one side. The first 

 arises at a point 4 cm. from the base ; and the others after 2'5, 3, and 10 cm. 

 consecutively. The lowest branch is broken, and is 13 cm. in length, but 

 was evidently much longer ; the others are 5'5, 10, and 15 cm. respectively 



(fig. 105). 



Tlie main stem after the origin of the first branch and all the branches 

 are markedly flattened in tlie plane of ramification. 



The diameter of the main stem near the biise is 2 mm., and its greatest 

 breadth in the flattened portion 3 mm. The branches vary considerably 

 in thickness. The colour of the colony is a pale orange-yellow ; but the 

 verrucac are more reddisli. The coeueuchyma has a very granular surface ; 

 it is nearly 1 mm. in thickness in the branches, but tliinuer in the older 

 parl«, where the axis is proportionately lai"ger. 



The polyps occur on tlic branches and also on tlie main stem, except on 

 the portion Ixjlow the origin of the firet branch ; tlicy are distributed in two 

 longitudinal series on t!ie sides of the branches ; the flattened aspect is broad, 

 anil quite devoid of polyps. In each series this is a single row ; but o\er- 

 crowding or the interijosition of young fonns sometimes obliterates the 

 symmetiy (fig. 106). 



The verrucao, when retracted, arc lnw, truncated cones, and often show 

 very distinct wrinkling ; they project very little beyond the coenenchynia. 

 llany "f the anthocodiac are only partially withdrawn ; and the infolded 

 tentacles appear to form a cone; on furliicr retraction their bases form a 

 Iiorizontal pseudo-operculum, and the verrucac present a very shrunken 

 appearance. The tentacles are eventually quite covered up by the inturned 

 sides of the vermcae. 



The canal system is typical and well defined ; the two main canals, 

 corresponding in position to the bare tracts, are lai-ge ; and a depression is 

 sometimes visible owing to a collapse of the walls. 



The axis is thin, cylindrical, composed of concentric hmiinae, and markedly 

 calcareous. It is yellow in colour ; and the surface is striated, two grooves 

 slightly larger than the othera being seen in some places. 



The spicules (fig. 107) consist of the following types, with measurements, 

 length by breadth, in millimetres. 



(a) Double-clubs, with a short constriction and with almost hemispherical 

 heads, veiy irregular in outline, covered with few large warts: 

 008 X 0-042 ; 0076 x 0046 ; 0076 x 042. 

 (6) Elongated double-clubs, with rounded ends, and openly-warted : 

 008 X 0038 ; 008 x 0034. 



