190 CYCLOCARPINE [ TELOCHISTES 
spores colourless or brown, l-septate, with thick outer walls and 
septum, the latter generally pierced by a longitudinal canal (polari- 
locular), rarely simple or 3-septate. Spermogones chambered, 
the sterigmata cellular (arthrosterigmata), with short pleuro- 
genous spermatia. 
The genera in this order are distinguished in most cases by the 
peculiarly septate spores. The median septum develops by an 
ingrowth from the outer wall, and though occasionally a narrow 
band, it sometimes broadens to such an extent that the lumen of the 
cells is reduced to a small space. A few species with simple or with 
3-septate spores are included in the genera, owing to other typical 
characters, such as the form of the spermogones, &c. 
Parietin, a yellow acid which yields an immediate purple or 
crimson colouration on the application of potash, is characteristic of 
several of the genera: of all those with yellow-coloured thalli except 
Candelariella, The latter genus is however included in the order 
as the spores, though mostly simple, often become septate and 
polarilocular. 
The British genera are :— 
Parietin present (yellow lichen acid coloured 
crimson or purple with potash). 
Spores colourless, usually 1-septate. 
Thallus fruticose, yellow .................. 45. Teloschistes. 
Thallus foliose, yellow: --..12026 «1.022 ese 46. Xanthoria. 
Thallus squamulose or crustaceous, 
mostly yellowWar 7... cs. noses ences 47. Placodium. 
Parietin not present. 
Spores colourless, at first simple, often many 
in the ascus. 
Thallus crustaceous ioc. sealiaccceasneane eee 48. Candelariella. 
Spores brown, usually 1-septate. Colour 
various. 
Thallus foliose, rarely fruticose or sub- 
fUbiCOBE: 25). sss jscccyaen- case aeeR ee eens 49. Physcia. 
Thallus squamulose or crustaceous ...... 50. Rinodina. 
45. TELOCHISTES Norm. in Nyl. Mag. Naturvid. Christ. vii. 
p. 228 (1852) excl. Phyllothalle &c. Borrera Ach. Syn. Lich. 
p- 220 (1814) pro parte; 8S. F. Gray Nat. Arr. i. p. 434 pro 
parte ; Hook. Fl. Scot. ii. p. 56 & in Sm. Engl. Fl. v. p. 222 pro 
parte. Physcia Schreb. Gen, Pl, ed. 8, ii. p. 768 (1791) pro parte ; 
Mudd Man. p. 111 pro parte; Cromb. Lich. Brit. p. 37 & 
Monogr. i. p. 294 pro parte; Leight. Lich. Fl. p. 141; ed. 3, 
p. 130 pro parte. (Pl. 45.) 
Thallus fruticose, brightly coloured, yellow, upright or partly 
decumbent, the fronds branched, cylindrical or compressed, 
attached at the base; structure radiate, the cortex of longi- 
tudinal hyph (fibrous). Algal cells Protococcus. Apothecia 
