LICHITiA.] 



81 



Tribe I. LICHINEI Nyl. Mem. Soc. Cherb. ii. (1854) p. 8 ; 

 Syn. i. p. 88, Stiz. St.* Gall. Nat. Ges. 1876, p. 193. 



Thallus small, fruticulose or radiato-laciniate, firm or fragile ; 

 gonimia elongate > seriately moniliform, subconnate. Apothecia 

 small, lecanorine, lecideine or sub-biatorine, paraphyses slender or 

 thickish ; spores 8nae, ellipsoid, simple or septate. Spermogones 

 tuberculose, with simple sterigmata or jointed sterigmata. 



The principal characteristic of this tribe is to be found in the gonimia 

 being moniliformly arranged through long: series. They are also much less 

 connate than in Gonionema, so that the affinities of the tribe ai-e rather with 

 this family. Of the four genera of which it is composed, only one is at 

 all common in Great Britain. 



8. LICHINA Ag. Syn. Alg. (1817) p. xii Tul. Ann. Sc. Nat. 

 ser. 3, xvii. (1852) p. 87 ; Nyl. Syn. p. 88. Thallus fruticulose, 

 cartilaginous, dicboto- 

 mously branched, within 

 parallelly lineari-cellu- 

 lar ; gonimia arranged 1 

 chiefly under the cortical 

 layer, bluish or glaucous- 

 bluish. Apothecia ter- 

 minal, in globose thalline 

 receptacles, lecanorine ; 

 spores simple, colourless ; 

 paraphyses slender, not 

 crowded ; hymenial gela- 

 tine not coloured with 

 iodine. Spermogones 

 terminal, with simple 

 long sterigmata and ob- 

 long spermatia. 



This small genus, though 

 fucoid in appearance, be- 

 longs in all essential cha- 

 racters to Lichens. The 

 few species of which it 

 consists are strictly social 

 in their habit, and often 

 extensively cover the other- 

 wise barren maritime rocks. 

 It is in various respects 

 somewhat parallel among Lichina 

 the Colkmacei to Sphesro- (1) 

 phorus amongst the Li- 

 chenacei. The apothecia 

 are truly lecanorine,though 



pyrenodean in appearance, 

 around them. 



Fig. 5. 



ygmcea Ag. a. Section of apothecium 

 of a spermogone (2), x30. b. Section 

 of thallus, X2(JO. c. Gonimia, x350. d. Theca 

 and paraphysis, X 350. e. Two spores, X 500. 

 /. Sterigmata and spermatia, X500. 



while the spermogones are often situated 



