NEW OR CRITICAL BRITISH ALGAD. 
57 
Leptonema , it appears to be quite distinct from Elachista. The 
plurilocular sporangia on British specimens are formed by transfor- 
mation of the upper cells of the assimilation filaments ; in none of 
our specimens do they form Ectocarpoid-like sporangia as figured 
by Herr Gran, but they very closely resemble Reinke’s figure 
(“Atlas,” Tab. 10, Figs. 6 and 8). And our plant certainly 
appears to belong to the same genus as the specimens of Leptonema 
fasciculatum , kindly sent to us by Prof. Reinke himself. 
The new genus Phceociadia, which in more than name appears 
to resemble the new genus Phceostroma, Kuckuck (“ Reinbold’s 
Die Phamphyceen der Kieler Fohrde, iv., p. 43), is thus described 
by the author: — 
*' Thallus composed of creeping filaments bearing branches at 
and below the apex, the older portions forming a pseudoparenchy- 
matous crust of 1-3 layers of cells, without any erect filaments. 
Unilocular sporangia arising from transformation of the vegeta- 
tive cells. Plurilocular sporangia unknown.” 
Ph. prostrata . — Thallus of irregular outline 1-3 mm. in 
diameter, 20-30 p thick, near the edge formed of a single layer of 
cells, the central portion being made up of two or rarely three 
strata. Vegetative cells elliptic, sometimes rounded, or 4-many 
angled, 10-20 p in diameter. Unilocular sporangia hemispherical 
or ellipsoidal, about 20 p in diameter, formed from the cells of the 
upper strata in various places and forming wart-like excrescences. 
The paper is of interest as dealing with the flora of a district 
which, although so near Christiania, has attracted so little notice 
from algologists. The plates are clear and appear to be accurate. 
INDEX LICHENUM BRITANNICORUM. 
By the Rev. J. M. Crombie, F.L.S. 
PART III. 
( Continued from p. ll.J 
f. Stirps, L. sabuletorum. 
Sp. 105 L. Nasgelii ( Hepp .), Stiz. 
106 L. sabuletorum, (Elk.), Nyl. 
/3. monophragmia, Nyl. 
107 L. lubens, Nyl. 
108 L. triplicans, Nyl. 
109 L. Dufourii (Ac/i.), Nyl. 
110 L. leucophasopsis, Nyl. 
111 L. sphaaroides ( Deles .), Smmrf. 
112 L. alabastrites, Nyl. 
113 L. leucoblephara, Nyl. 
114 L. albidocarnea, Nyl. 
115 L. herbidula, Nyl. 
