18 



EPHEBACEI. 



[gonionema. 



satisfactory diagnosis, and are consequently omitted. Among these are 

 several species of Sirosiphon, e. g. S. scuicola Naeg., S. alpinum Kiitz., 

 S. pulvinatus Br^b., S. ocellatus Kiitz., whicli occur in Great Britain and 

 Ireland. According to Nylander, in Lamy Mt. Dor. p. 1 (note), Itaco- 

 dium ebetieimi (Dillw.), which from general appearance might be sup- 

 posed to belong to this tribe, has no analogy with Sirosiphon, but is 

 quite difiereut in struc- 

 ture, containing gonidia, 

 and is probably some 

 peculiar sterile Lepraria. 



1. GONIONEMA Nyl. 



Mem. Soc. Cherb. iii. 

 (1855) p. 163; Syn. i. 

 p. 88. — ThaUus byssaceo- 

 fibrillose, tubuliform, in- 

 tricate ; gonimia sub- 

 moniliformly connate in 

 one continuous series. 

 Apothecia biatorine or 

 gyalectoid ; spores 8nae, 

 simple, paraphyses slen- 

 der ; hymenial gelatine 

 (especially the thecse) 

 bluish, becoming wine- 

 red or tawny wine- 

 coloured with iodine. 

 Spermogones lateral, or 

 terminal, globose ; ste- 

 rigmata simple, slender ; 

 sperm atia oblong, very 

 minute. 



Various Scytonemas 

 probably belong to this 

 genus. If this be so, the 

 more recent name must 

 give place to that of 

 Scytonema Ag., in its 

 stricter sense. 



1. G. velutinxun Nyl. 



Mem. Soc. Cherb. iii. 

 (1855) p. 163.— Thallus 

 very thin, densely pan- 

 nose, intricate, brownish 

 when moist, dark-brown 

 when dry. Apothecia 



Fig. 1. 

 Goniuoiema velidinum Nyl. — a. Filaments with 

 two apothecia, X 30. b. Vertical sections of 

 two apothecia, X 30. c. Filaments with 

 three spermogones, X 30. d. Short frustule of 

 thallus, and d' transverse section of the same, 

 X 3-W. c. Apex of a filament containing a 

 meiogonimium, X 200, and e' fragment of a 

 syngonimium composed of four gonimia, 

 X 350. /. Sterigmata and spermatia, X 500. 

 g. Theca and paraphyses, X 350. h. Three 

 spores, X 500. 



minute, tei'minal, ap- 

 presscd, somewhat concave, dark-brown, pale within, the margin 

 tumid; spores ellipsoid or oblongo-cllipsoid, 0,0] 0-0,015 mm. long, 

 0,006-0,007 mm. thick.— Nyl. Syn. i. p. 88, t. 1. f. 11 ; Leight. 



