Mr. E. Parfitt on two new Species of Freshwater Polyzoa. 171 
thallus. Thus Lecanora subfusca, which exhibits the yellow 
reaction, is distinguishable at once from ZL. umbrina, dispersa, 
and conferta, in which no such reaction is visible. 
The same reactive operates on other Lichens by producing a 
yellow colour which quickly changes into a red or purple. Of 
this a good example is Lecanora cinerea, which is thus distin- 
guished from gibbosa (and its varieties calcarea, lacustris, &c.), 
in which there is no reaction. The L. cinereo-rufescens, Anazi, 
Langob. 73, has the same reaction as cinerea, proving it to be 
only a variety of that species, whilst the true cinereo-rufescens 
(and its forms diamarta and obscurata) has no reaction. The 
reaction takes place also in Lecanora oculata, blanda, ochroidea, 
whilst there is none in L. mutabilis and verrucosa. 
To the above many other instances might be added ; but these 
will be sufficient to show the applicability of these valuable tests. 
XXVIII.—On two new Species of Freshwater Polyzoa. 
By E. Parrirt, Ksq. 
| Plate XII] 
To the Editors of the Annals and Magazine of Natural History. 
GENTLEMEN, 
I have much pleasure in introducing to your notice two new 
species of freshwater Polyzoa met with by me in my investiga- 
tions of the Devonshire fauna, in the compilation of which in a 
catalogue form, with notes and observations, I have been engaged 
for nearly two years; and I hope by-and-by to publish it. 
The tracings enclosed are made from my own drawings taken 
from the life, which I hope your artist will be able to use. 
As an appendix to Prof. Allman’s beautiful monograph of the 
Freshwater Polyzoa, I beg leave to add the description of the 
statoblasts of Paludicella Ehrenbergi, as they had not been seen 
by the learned author, and I have been fortunate enough to 
meet with several :— 
The outline is a very elongated ellipse, the cell very small as 
compared with the very broad border, plano-convex; the cell 
reddish brown, the annulus or border bluish purple, beautifully 
reticulated and reflecting the prismatic colours. 
They were arranged three in each tube, placed end to end. 
I have met with a variety of Paludicella which I shall have 
something to say about at some future time. 
I am, Gentlemen, 
Yours obediently, 
Exeter, Aug. 3, 1866. Epwarp Parrirt, 
