232 
VII. Rhizopoda. 
1. Acyttaria (Monothalamia and Polythalamia) . 
2. Heliozoa ( Actinospheerium Eichhornii). 
3. Radiolaria (Monocyttaria and Polycyttaria). 
"V III. Spongije. 
1. Autospongiae. 
2. Petrospongiae. 
Since the separation of these eight groups of Protista, a 
new group of organisms of the lowest class has become 
known, which cannot be placed in any of these eight divisions 
without violence, and which, like the latter, exhibits such a 
combination of animal and vegetable characters, that they 
can just as little be recognised as true plants as true animals. 
These are the remarkable Labyrinthulea ( Labyrinthula vitel- 
lina, L. macrocystis ) which were discovered in the harbour 
of Odessa 1 by Cienkowski, to •whom the natural history of 
the Protista is so much indebted. At all events, these 
must be provisionally considered as an entirely separate 
group of Protista. 
(To be continued.) 
On Raphides, Sph^eraphides, and Crystal Prisms ; espe- 
cially as to how and where they may be easiest found and 
discriminated. By George Gulliver, F.R.S. 
What are the distinctive characters of raphides, sphae- 
raphides, and crystal prisms ? How may they be surest and 
easiest found, and in what common plants ? Is not the 
occurrence of raphides very inconstant, seeing that either 
their presence or absence in one and the same plant is alter- 
nately affirmed and denied, and that they are not always 
found in those very species or classes, such as the “ tulip- 
bulb ” and “ monocyteledons generally,” in which we are 
directed to look for them ? 
Such questions as these so often arise that the answers now 
proposed thereto, with a few incidental observations on the 
significance or use of plant-crystals, may prove convenient 
and useful to the readers of the 4 Quarterly Journal of Micro- 
1 ‘ Arcliiv fur Mikrosk. Anat.,’ vol. iii, ] 867, p. 2 74, Taf. xv — xvii. 
