__ PHYSCIA. | PHYSCIEI, 319 
smaller.— Physcia obscura subsp. lithotea Cromb., Grevillea, xv. 
p- 78; form lithotea Leight. Lich. Fl. ed. 3, p.187. Parmelia eyclo- 
selis (3. lithotea Ach, Meth. (1803) p. 199. 
Subsimilar to P. odscura, but differs in being firmer, more or less furfu- 
raceous, and especially in the cellular structure of the cortex, which 
consists of rounded cells, being more distinct. In age nearly the whole 
thallus and the margins of the laciniz are covered with a dark furfur. 
The state sciastra (Ach. Meth. Suppl. p. 49) differs merely in being 
darker and sorediate only at the margins of the lacinie. The apothecia 
when present (for it is usually sterile) are small and few. 
Hab. In depressions of rocks which are frequently moistened by the 
sea and by Jakes and streams in maritime and mountainous districts.— 
Distr. Local and scarce in N. England, N. Wales (jide Leight.), among 
the 8. Grampians, Scotland, and in N.W. Ireland.—B. M.: Near New- 
ton, Cleveland, Yorkshire; Teesdale, Durham. Loch Dochart and Ken- 
more, Perthshire. Connemara, co. Galway. 
23. P. ulothrix Nyl. Flora, 1875, pp. 360, 442.—Thallus orbicu- 
lari-stellate, greyish-glaucous or dark-brown, sometimes sublivid, 
esorediate ; beneath black-fibrillose ; laciniee discrete, narrow, linear, 
multifid, plane, ciliate at the margins, the cilia rigid, horizontal 
(K~, CaCl). Apothecia moderate, dark-brown, the thalline mar- 
gin entire, at length inflexed, the receptacle at the base black- 
fibrillose ; spores oblong, 0,015-25 mm. long, 0,009-12 mm. thick. 
—Cromb. Linn. Soc. Journ. Bot. xvii. p. 571.— Physcia obscura var. 
ulothria Cromb. Lich. Brit. p. 389; Leight. Lich. Fl. p. 149, ed. 3, 
p. 137. Borrera obscura 8. ulothric Mudd, Man. p.110. Parmelia 
ulothriw Tayl. in Mack. Fl. Hib. ii. p.146. Lichen ulothria Ach. 
Prodr. (1798) p. 113. Lrchen virellus Eng. Bot. t. 1696 (lower 
fig.). Lichen ciliatus Dicks. Crypt. fasc. iii. p. 16; With. Arr. 
ed. 3, iv. p. 30. Lichen stellaris var. 4, With. l.c. p. 31. Lichen- 
vides viride, segmentis angustis distortis, scutellis pullis Dill. Muse. 
178, t. 24. f. 724.—Brit. Evs.: Leight. n. 80. 
Usually regarded by more recent authors as a variety of the preceding ; 
this was rightly viewed by Acharius as a distinct species, as warranted 
more especially by the peculiar character of the marginal cilia and in a 
minor degree by the radiating fibrillose receptacle of the apothecia. In 
this latter respect, as already observed, it is analogous to subsp. Parmelia 
carporhizans, though in old plants this character is less apparent. When 
sterile it is readily distinguished by the horizontal marginal cilia of the 
thallus. The apothecia are numerous and often crowded, and the spermo- 
gones, which seem to be rather rare, are as in P. obscura. 
Hab. On the trunks of trees, rarely on old pales and walls in maritime 
and upland districts.—Distr. Occurs only here and there in England, 8. 
Scotland and thé Highlands, and S. Ireland—B. M.: Lakenham ‘and 
near Yarmouth, Norfolk; Brighton and Albourne, Sussex; near Pen- 
zance, Cornwall: Cirencester, Gloucestershire; Gopsall Park, Leicestei- 
shire ; Buxton, Derbyshire; near Worcester. New Galloway, Kirkeud- 
brightshire ; Appin, Argyleshire ; Finlarig, Killin, and Glen Fender, Blair 
Athole, Perthshire. Carrigaloe, near Cork. 
