COLLEMA. ] COLLEMELI. 57 
the gonimia being not moniliform but glomeruloso-congested. The apo- 
thecia are usually scattered over the whole thallus almost to the apices of 
the lacinize. 
Hab. On shady calcareous rocks and walls in maritime and upland 
districts.—Distr. Sparingly here and there in Great Britain, 8. and W. 
Ireland.—B. M.: Mendip Hills and near Yatton, Somersetshire ; Dovedale 
and Buxton, Derbyshire; Oswestry, Shropshire; Nant Glyn, Denbigh- 
shire; Settle, Yorkshire; Teesdale, Durham; Haversham Head and 
Cunswick Scar, Westmoreland; Lamplugh, Cumberland. Achosragan 
Hill, Appin, and island of Lismore, Argyleshire; shores of Loch Tay and 
Ben Lawers, Perthshire. Middleton, near Cork; Kenmare and O’Dono- 
ghue’s Prison, Killarney, co. Kerry; Kylemore, co. Galway. 
25. ©. isidioides Nyl. ev Arn. Flora, 1870, p. 232.—Thallus 
granuloso-aggregate (isidioid), blackish, in subpulvinate glomeruli. 
Apothecia and spermogones unknown.—Nyl. Flora, 1883, p. 98; 
Cromb. Journ. Bot. 1885, p. 195. 
The place of this species in the genus is uncertain in the absence of 
fructification. Detected by Arnold in the Bavarian Alps, Nylander 
observes that the “thallus consists of a congeries of syngonimia (sub- 
globose or oblongo-difform), with the filaments often indistinct.” 
Hab. On caleareous rocks in mountainous districts.—Dizst. Gathered 
only in N.W. England (Warton Craig, Westmoreland). 
15. COLLEMODIUM Nyl. ex Lamy, Bull. Soc. Bot. Fr. 
t. xxv. (1878) p. 841; Nyl. Flora, 1875 (ut subgenus).—Thallus 
small or submoderate, 
variously lobed or 
subfruticulose ; corti- 
cal layer somewhat 
distinct ; gonimia 
more or less scattered, 
partly moniliform. 
Apothecia urceolate, 
lecanorine, rarely bi- 
atorine; spores 8ne, 
8 @e 
Se 
B&B 
ovoid or ellipsoid, Fig. 14. 
colourless, variously Collemodium fluviatile Nyl.—a. Vertical section 
septate and divided ; of thallus, x275. 6. Gonimic granules sepa- 
hvmenial gelatine rated from the cells. 
deep blue with iodine. Spermogones with jointed sterigmata and 
straight spermatia obsoletely incrassate at either apex. 
Instituted by Nylander for various plants previously arranged chiefly 
under Collema. From Collema it differs in the cortical layer being 
distinct, though usually but slightly apparent. It thus forms a transition 
between Collema and Homodium, a subgenus of Leptogium to which it 
is closely related. The fructification is similar to that of Leptogium. 
1. C. biatorinum Nyl. ev Cromb. Grevillea, xv. (1886) p. 12.— 
Thallus effuse, minutely granuloso-lobulate, imbricate, brown or 
