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 L. 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, Anzi, 

 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 neiv Species of Freshwater Polyzoa. 

 By E. Parfitt, Esq. 



[Plate XII.] 

 To the Editors of the Annals and Magazine of Natural Histmy. 

 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 Ehrenbergii, 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 brovVn, 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. Edward Parfitt. 



