76 ON THE LICHENS IN DR. WITHERING^S HERBARIUM. 
Im. nigrescens^Collema nigrescens (Hiids.), — (fertile specimens 
from Griffith and from Dcks. Hort. Sic. 22). 
L. cxistatus=(7nZ/ma tenax var. coronata, (Kbr.), — (specimens 
from Dickson s. n. L. crispus, and from Griffith). 
L. &itixi^t‘}xs=Leptogiuni sinuatum (Hnds.), — (fertile specimens 
from Dickson and Griffith). 
L. fascicula»is=Go//ma fasciculare (L.), — (specimen from 
Dickson), and ^s>o=Leptogium (Collemodium) inicropTiyllum 
(Ach.), — (specimen from Griffith). 
L. crispus= Co/Zema cheileum^ (Ach.), — (fertile specimen from 
Mr. Woodward). 
Ii. xupestris. Of this there is no specimen. 
L. fluviatilis=Zep^9'm7/i fluviatile (Huds.), — (specimens from 
Griffith, fertile ; from Dickson and R. Brown, sterile). 
Sphaeria &ce^^xiA.=Arthonia cinnabarina^ var. Kermesina 
(Schser.), — (specimens from Griffith). 
SIROSIPHON SAXICOLA (Nceg). 
Filaments minute, curved, variously branched, closely crowded 
into a thin dark crust or unevenly scattered pulvinuli ; vagina nar- 
row, fuscous ; cellules in single series, growing denser and nucleate 
with age ; fruit not seen. 
On damp rocks, rare ; Ennerdale Lake side, Cumberland, 
1881. 
This lichen grows upon damp rocks, or rocks down which water 
trickles rather than flows ; its colour when wet is dark olive, when 
dry black. It is sparsely scattered, more thickly clustered in some 
spots than others, and looks like a thin dark plush upon the stone. 
With a lens, the filaments can be distinguished entangled and de- 
pressed, and under the microscope they appear variously branched, 
somewhat mammillose and obtuse. The cellules are defined, 
roundish at the apices of the ramuli, but becoming oval, oblong or 
quadrate, as they are crowded down into the older parts of the 
filaments, where they are frequently double. The ramuli are 
merely lateral developments of the central cellules, and these run 
out into branches not by bursting, but by diverting the vagina. 
Dr. Nylander has examined this plant and pronounced it the 
species named, and we know of no previous record in Great 
Britain of which it is a synonym. How far it may differ from 
Scytonema minutum Ag. (Mackay’s FI. Hibernica, p. 236) we can- 
not sav, as we have not seen the latter. 
Hartlepool. 
W. Johnson. 
