DIRIVA.] 



LECAXO-LECIDEEI, 



491 



red with iodine. Spermogones tuberculoso-immersed, with simple 

 sterigmata aud acicular, arcuate spermatia. 



A small genus closely allied to Leca- 

 norn, from which it dilfers chietiy in the 

 character of the hypothecium. In this 

 respect, as also in their fdrni, the apo- 

 thecia resemble those of Hoccella. 



1. D. repanda Xyl. Mem. Soc. 

 Chcrb. V, (^ISoT) p. 110. — Thallus 

 determinate, thick, tartareo- farinose, 

 tuberculoso-unequal, subeffigiirate at 

 the circumference, white (Kt' + yellow, 

 CaCl -\- red) ; bypothallus white. 

 Apothecia elevated, piano-depressed, 

 at first closed, then expanded and di- 

 lated, black, caesio- or white-pruinose ; 

 the thalline margin thick, obtuse, 

 more or less intlexed ; spores often 

 slightly curved, 0,0i;7-30 mm. long, 

 about 0,004 mm. thick. — Cromb. 

 Journ.Bot. lS71,p. 17S ; Leight. Lich. 

 Fl. p. 235, ed. 3. p. 22(j. — ParmeUa 

 repanda Fr. Lich. Eur. (1S31) 

 p. 177. 



Fig. 69. 



Birina repanda Nyl. — a. A theca 

 and paraphysis, X 350. b. 

 Three spores, X 500. c. Ste- 

 rigmata and spermatia, X 500. 



A plant chiefly of S. Europe and X. Africa which finds its way to a 

 few localities in our Islands. The peculiar apothecia are numerous, at 

 times crowded and difibrm with the thalline margin then fiexuose. In 

 sterile specimens the spermogones are abundant, with sterigmata 0,010 mm. 

 long, 0,001 mm. thick. The corticolous form {Lecanora Ceratonice Ach. 

 Lich. Univ. p. 301, t. 7. f. 5) does not occur with us. 



Hab. On rocks in maritime districts. — Distr. Only sparinglv in the 

 Channel Islands, S.W. England, aud X. Wales. — B. M. : La Coupe and 

 Rozel, Island of .lersey. Portland Island, Dorsetshire; Great Orme's 

 Head, Caruai'voushire, 



Subtribe III. PERTUSARIEI Xyl. Lich. Scand. (1S61) p. 177. 



Thallus variously crustaceous, continuous ; gonidial layer con- 

 taining typical eugonidia. Apothecia more or less inclosed in 

 thalline verrucse, punctiform or with the disc expanded and leca- 

 noroid ; spores variable in number, simple. Spermogones with 

 simple sterigmata. 



Arranged by many authors among the Pyrenocarpei from the fruit of 

 both being frequently subsimilar. As, however, the more developed 

 forms of the apothecia in Pertusariei resemble those of mauy Leoanorci, 

 its two genera are more appropriately included in this tribe. 



62. PERTUSARIA DC. Fl. Fr. ii. (leOo) p. 13D ; Xyl. Mem. 



