COLLEMA.] COLLEMEF. 41 



globose. The apothecia are generally abundant, almost obliterating the 

 tballus, and becoming like it blackish when dry. The preceding species 

 is intermediate between this and C. chalazanum. 



Hob. Among mosses on old walls in shady places in upland districts. 

 Dixlr. Very local, though plentiful where it occurs in W. England, 

 S. Wales, and N.E. Ireland," probably elsewhere overlooked. B. M.: 

 Near Cirencester, Stroud, and Ablington, Gloucestershire; Pembroke- 

 shire. Near Belfast, co. Antrim. 



b. Hymenial gelatine bluish, with iodine. 



4. C. confertnm Xyl. Flora, 1867, p. 330. Thallus small, 

 turgidly squamulose, blackish-brown ; squamules crowded, usually 

 cyathoid or podetiiform, almost all fertile. Apothecia small, urceo- 

 lato-impressed, one at the summit of each thalline squamule or 

 lobule, subconcolorous, the margin tumid ; spores ellipsoid or 

 fusiformi-eUipsoid, 0,017-23 mm. long, 0,008-10 mm. thick; 

 paraphyses slender. Leight. Ann. Mag. Nat. Hist. ser. 3, xx. 

 p. 259 ; Lich. Fl. p. 18, ed. 3, p. 16 ; Cromb. Lich. Brit. p. 4 ; 

 Journ. Bot. 1874, p. 333. Collema turgidum var. confertum Ach. 

 L. U. (1810) p. 634. 



The peculiar squamulose thallus and the situation of the apothecia at 

 once distinguish this from other British species of Collema. It is allied 

 to C. lepideum Nyl., a West-African plant, and the two form a distinct 

 group, characterized by the thallus and the reaction of the hymenial 

 gelatine. No authentic British specimen has been found in recent years; 

 and indeed the plant is known only from the original specimen sent by 

 Turner to Acharius, and from two fragments in Herb. Kew and Brit. 

 Mus. 



Hob. Amongst mosses on the ground in maritime tracts. Distr. Known 

 only from E. England. B. M. : Dunwich, Suffolk. 



B. EUCOLLEMA Cromb. Journ. Bot. 1874, 

 p. 333. Thallus variously lobed, 

 rarely entirely granulose ; gonimic 

 granules usually moniliform. Apo- 

 thecia lecanorine ; spores septately Fig. 11. 

 divided, irregularly murali - locular, Collema pulposum Ach. 

 ovoid or ellipsoid ; hymenial gelatine Six spores, x 500. 

 bluish with iodine ; spermogones with 

 jointed sterigmata. 



a. Thallus entirely granulose. 



5. C. terrulentum Nyl. Flora, 1874, 

 p. 306. - Thallus small, scattered, thin, 



granulose, olive-brown or brownish-black. Four spores, x 500. 

 Apothecia small, concave, reddish-brown, 

 the thalline margin thickish, entire; spores ellipsoid or oblong, 

 submurali-divided (usually with 5 transverse septa), 0,018-24 mm. 



