COI.LKMA.] 



COTJ.EMEI. 



the goniuiia being not moniliform but glonieruloso-congested. The apu- 

 thecia are usually scattered over the whole thallus almost to the apices of 

 the laciuise. 



Hah. On shady calcareous rocks and walls in maritime and upland 

 districts. — Dtsfr. Sparingly here and there in Grrat Britain, S. and W. 

 Ireland. — B. M. : Mendip Ilills and near Yattou, Somersetshire ; Dovedale 

 and Buxton, Derbyshire; Oswe.stry, Shropshire; Kant Glyn, Denbigh- 

 shire ; Settle, Yorkshire; Tc'csdale, Durham; Haversham Head and 

 Cunswick Scar, Wtstmoreland ; Lamplugh, Cumberland. Achosragan 

 Hill, Appin, and island of Lismore, Arg^yleshire ; shores of Locli Tay and 

 Ben Lawers, Perthshire. Middletou, near Cork ; Kenmare and O'Douo- 

 ghue's Prison, Killarney, co. KeiTy ; Kylemore, co. Gahvay. 



25, C. isidioides ISTj-l. ex Am. Flora, 1870, p. 232. — Thallus 

 granuloso-aggrcgate (isidioid), blackish, in subpulvinate glomeruli. 

 Apothccia 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 tlie absence of 

 fructification. Detected by Arnold in the Bavarian Alps, Nylander 

 observes that the "thallus consists of a congeries of syngoniuiia (sub- 

 o-lobose or oblougo-ditform), with the filaments often indistinct." 



Mah. On calcareous rocks in mountainous districts. — Distr. Gathered 

 only in N.W. England (Warton Craig, Westmoreland). 



15. COLLEMODIUM Xyl. ex Lamy, Bull. Soc. Bot. Fr. 

 t. XXV. (1878) p. 341; jS'yl. Flora, 1875 (ut subgenus). — Thallus 

 small or submoderate, 

 variously lobed or 

 subfruticulose ; corti- 

 cal layer somewhat 

 distinct : goniraia 



more or less scattered, 

 partly moniliform. 

 Apothecia urceolate, 

 lecanorine, rarely bi- 

 atorine ; spores 8n[e, 

 ovoid or ellipsoid, 

 colourless, variously 

 septate and divided ; 

 hymenial gelatine 

 deep blue with iodine. 



Fig. 14. 



CoUemodium fiuviatile IVyl.- 



-a. Vertical section 



of thallus, x275. h. Gonimic granules sepa- 

 rated from the cells. 



Spermogones with jointed sterigmata and 



straight spermatia obsoletely incrassate at cither apex. 



Instituted by Nylander for various plants previously an-anged chiefly 

 under Cullema. From Collema it differs in the cortical layer being 

 distinct, though usually but shghtly apparent. It thus forms a transition 

 between Collema and Homodium^ a subgenus of Leptuijiuin to which it 

 is closely related. The fi-uctitication is similar to that of Leptogium. 



1. C. biatorinum Nyl. ex Cromb. Grevillea, xv. (1886) p. 12. — 

 Thallus effuse, minutely granuloso-lobulate, imbricate, brown or 



