750 Scientific Proceedings, Royal Dublin Society. 
biceps (fig. 12), CO. fusus (fig. 18), C. divergens (fig. 16), (both in the 
motile and spore-producing stages), C. michaelis, and two species of — 
Dinophysis, apparently D. norvegica and D. acuminata (fig. 14). 
To these may be added Prorocentrum micans (fig. 17). Of the 
Radiolaria we found only Dictyocha trifenestra (fig. 15). 
In addition to the forms just described, and which can be 
more or less easily referred to known groups and genera, we came 
across, in this investigation, several organisms which, so far as we 
know, have not been described. Among these were two or three 
specimens of a minute sphere (fig. 1), somewhat larger than a 
coccosphere (7.e. about 05 mm. in diameter). It consists of a mass 
of protoplasm, carrying in it yellow-brown colouring matter, and 
eovered by a delicate pellicle, in which are supported a number of 
T-shaped spicules. On treatment with dilute hydrochloric acid, 
the pellicle remains, but the spicules dissolve. The spicules seem 
each to arise from an oval plate carried in the pellicle. From the 
peculiar spicules we may call this an “ Echinosphere.”’ 
About the same size as the Hchinospheres, and occurring also 
in the same sporadic manner, was another spherical body (fig. 3). 
In this the protoplasmic basis was covered over with oval scales of 
calcium carbonate. A short conical point rose from the centre of 
each scale, and projected from the surface of the sphere. From 
the peltate scales, we term this a ‘ Peltasphere.” This body we 
also found in surface-water gathered off Valencia Island. Within 
the ‘ Peltasphere,” one or more greenish granules could be 
observed. 
In much greater abundance than the Hchinospheres, or 
Peltaspheres, were two cyst-like structures, resembling Hhrenberg’s 
Xanthidia and Pyxidicula. Ehrenberg described these from the 
chalk, and, so far as we know, they are not described as being 
recent. ‘The forms resembling Pyxidicula are spherical shells of a 
chitinous substance, golden brown in colour. Their surface is 
finely punctate. ‘They are about -084 mm. in diameter (fig. 10). 
Sometimes they are complete, and contain coarsely granular 
protoplasm within them, which appears to have an inner and 
more delicate pellicle covering it inside the chitinous shell, some- 
times they are irregularly ruptured, or opened with a circular or 
tri-radiate slit. These Pyxidicula seem to us to be, in all pro- 
bability, encysted protozoa. 
