<OL1,EMA.] COLLEMK1. 53 



Approaches f. marginal?, but distinguished by the larger spores, which, 

 as observed by Nylander I. 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. 



Hob. On calcareous rocks in upland districts. Distr. Found only in 

 X.\V. Ireland. B. M. : Tullywhee Bridge, co. Galway. 



18. C. cristatum Hoffm. Deutsch. Fl. ii. (1795) p. 101. Thallus 

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

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

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

 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. Sender. 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 subplicatile Cromb. Journ. 

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

 to the section of G. chalazanwn. As already observed, Lichen crista- 

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



From the closely allied C. melatnum this differs in the imbricato-aggre- 

 gate iacinia? with inciso-dentate margins, in the larger apothecia with 

 crei ulate thalline margin, aud in the slightly different spores. These 

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

 fi -ally distinct is doubtful. The apothecia, when fully developed, are of 

 considerable size, and only sparingly present. 



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

 land districts. Distr. Found only in W. England, the W. Highlands, 

 Scotland, and S.W. Ireland. B. M. : St. Michael's Tor, Devonshire : 

 near Cirencester, Gloucestershire. Island of Lismore, Argyleshire ; 

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



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

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

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

 more expanded and depressed at the circumference. Apothecia 

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

 blackish, the thalline margin thin, entire : spores oblong or f'isi- 

 formi-ellipsoid, more constantly 3- rarely 5-septate, locuiar, 0,0 J 8- 

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

 p. 132, 1874, p. 334 ; Leight. Lich. Fl. ed. 3, p. 22^-Oollema 

 midtifidum . polycarpon Schaer. Spic. (1842) p. 532. Oollema 

 styyium Scha3r. Spic. p. 544, Lich. Helv. n. 434 : Cromb. Journ. 

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

 observes in litt. that while C. stygium Del., may be the plant of 

 Schaerer, it is probably not pure, and is besides ouly 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. mel&num, but the characters 

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

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



