COI-LEMA.] COLLEMEI. o3 



Approaches f. marginale, but di3tin<niished by the larger spores, wliich, 

 as observed by Nylander /. c, entitle it to rank at least as a subspecies. 

 In the only two specimens seen by me the apothecia are numerous, and 

 almost crowded in the centre. 



Hab. On calcareous rocks in upland districts. — Distr. Found only in 

 N.W. Ireland. — B. M. : TuUywhee Bridge, co. Galway. 



18. C. cristatum HofFm. Deutsch. Fl. ii. (1795) p. 101.— ThaUus 

 intricately laciniate, thickish, olive- or blackish-green (I + red); 

 laciniae short, undulato-crisp, inciso-crenate at the margins. Apo- 

 thecia rather large, somewhat plane, reddish-brown, the thaUiue 

 margin at length crenulate ; spores fusiformi-oblong, somewhat 

 narrower at both apices, 3-septate, irregularly murali-locular, 0,026- 

 34 mm. long, 0,010-12 mm. thick. — Schaer'. Enum. (1850) p. 225: 

 Cromb. Journ. Bot. 1874, p. 334 ; Leight. Lich. Fl. ed. 3, p. 22.— 

 To this belongs as an old state Collema suhplkatiU Cromb. Journ. 

 Bot. 1874, p. 147, nonXyl. Flora, 1875, p. 297, which latter belongs 

 to the section of C. cluiJazanum. As already observed, Lichen crista- 

 tas Huds., Linn., &c. is a variety of Collema tena.r. 



From the closely aUied C. melcenum this differs in the imbricato-aggre- 

 gate iacinise with inciso-dentate margins, in the larger apothecia with 

 ere? ulate thalUne margin, and in the slightly diflferent spores. These 

 distinguish it in its typical condition, though whether they make it speci- 

 fi ^ly distinct is doubtful. The apothecia, when fully developed, are of 

 considerable size, and only sparingly present. 



Hah. Among mosses on old walls and on rocks in maritime and up- 

 land districts. — Distr. Found only in W. England, the W. IlighlancU, 

 Scotland, and S.W. Ireland. — B. ^1. : St. MichaeFs Tor, Devonshire : 

 near Cirencester, Gloucestershii-e. Island of Lismore, Argyleshire ; 

 Killin and Craig Tulloch, Perthshire. Killamey, co. Kerry. 



19. C, polycarpon Koerb. Par. (1865) p. 417. — ThaUus small, 

 radiato-laciniate, appressed, dark-green or reddish-black (I -f- pur- 

 plish-red) ; laciniae narrow, short, complicate, suberect in the centre, 

 more expanded and depressed at the circumference. Apothecia 

 small, numerous, plane, or at length, somewhat convex, dark-red or 

 blackish, the thalline margin thin, entire : spores oblong or fvsi- 

 f or mi-ellipsoid, more constantly 3- rarely 5-septate, locuiar, 0,018- 

 27 mm. long, 0,006-7 mm. thick. — Cromb. Joujn. Bot. (1873) 

 p. 132, 1874, p. 334 ; Leight. Lich. Fl. ed. 3, p. 22.— Collema 

 multifidum c. polycarpo^i Schoer. Spic. (1842) p. 532. Collema 

 stijgium Schaer. Spic. p. 544, Lich. Helv. n. 434 ; Cromb. Jcurn. 

 Bot. 1874, p. 334 ; Leight. Lich. Fl. ed. 3, p. .23. Jfylander 

 observes in litt. that while C. str/rjinm Del., may be the plant of 

 Schaerer, it is probably not pure, and is besides only a MSS. name, 

 while that of Schaerer and Arnold is C. polycarpon (conf. Flora, 

 1883, p. 105).— Brit. Exs. : Cromb. n. 103 ; Larb. Lich. Hb. n. 1. 



Might be taken for a smaller state of C. tnelcpnum, but the charactera 

 given separate it. The apothecia are usually abundant over the thaUus, 

 and sometimes are so numerous as almost to obUterate the laciniae. 



