remarkable Species of Cliona. 65 
brought about. Fig. 19 represents a very unusual form, in 
which the spines of the spicule have become bifurcate at their 
ends. 
Oliona subulata. 
Associated with the Js?s which furnished the preceding spi- 
cules, is a patch of Melobesia, in which also Cliona-burrows 
occur; but these, curiously enough, are occupied by a third 
species, the spicules of which are represented in PI. II. figs. 
26-28, and appear to belong to a new species, for which 
I propose the name of C. subulata. I should state that bur- 
rows of the two preceding species occur in the Melobesia along 
with this. 
Note.—While writing this paper I had occasion to refer 
to a specimen of Cliona occupying burrows excavated in a 
solid piece of limestone rock, which I had brought away with 
me from Dawlish. I had always taken my specimen to be 
C.. celata, and referred to it in order to determine whether it 
possessed diaphragms of any kind like those of (. mucronata. 
As to this my results were negative ; but an examination of its 
spicules showed that it differed from C. celata in the form of 
its flesh-spicules, while its skeleton-spicules are essentially the 
Fig. 2. 
Spicules of C. hnearis: a, skeleton-spicule; 6, variety of a, with rounded 
end and produced spine ; ¢ and d, varieties of a, with rounded ends 
(a-d x 140); e, flesh-spicules (x 435). 
same as those of C. celaia, Raphyrus Griffithsit, and Hali- 
chondria ficus. The flesh-spicule, instead of remaining rela- 
tively short and becoming spined, attains, as if by the sacri- 
Ann. & Mag. N. Hist. Ser. 5. Vol. i. 5 
