Fig. 
Fig. 
Fig. 
Fig. 
EXPLANATION OF PLATES. 
Prate XV. 
Illustrative of the genera Puacovium, DC., Nyl.; Sevamarra, DC.; Epuese, Fr., Born. ; 
a 
bo 
Licuina, Ag. ; Conuema, Ach, ¢ ; and Leprogrum,. Er, 
. Placodium murorum, DC.; Cork. Portion of thallus, showing apothecia a, and orange- 
coloured papillaform spermogones b. 
. Sterigmata and spermatia of same species. 
. P. circinatum, Pers., var. variabile, Pers.; Hepp. exs., 74. Thallus, bearing apothecia a, 
and brown, pellucid, punctiform spermogones }, 
. Section of the same spermogones, 
. P. circinatum, Pers.; Dereham Church. Sterigmata and spermatia, 
. Spermogones of same specimen; a, simple; 6, confluent,—in both cases irregularly stellate- 
fissured and pseudo-lecidine in aspect. 
. P, alphoplacum, Wahlb.; Scher. exs., 330. Portion of plant, bearing apothecia a, and 
punctiform or papilleeform spermogones b, perched on thalline warts. 
. P. fulgens, DC.; Hepp. exs.,194. Thallus, bearing apothecia a, and papilleform orange- 
red spermogones 6, 
. P. chalybeum, Duf.; Hepp. exs., 204. Portion of thallus, showing apothecia a, and 
punctiform spermogones ). 
. Section of the same spermogones. 
. One of the thalline areole, magnified to show the punctiform, immersed spermogones a. 
Sterigmata and spermatia of same plant. 
. P. candicans, Dub. ; Leighton exs., 218. Portion of thallus, showing a, punctiform sper- 
mogones ; and b, apothecia. 
. Section of the same spermogones. 
. Squamaria chrysoleuca, Sm.; Scher. exs., 345. Thallus, bearing a, apothecia; and 6, 
punctiform or papilleform spermogones, seated at b, on thalline warts; at c, about the 
subfoliaceous margins of the thallus. 
. Section of the same spermogones: «@, papilleeform ; 6, flattened, with depressed ostiole. 
. Sterigmata and spermatia of same species. 
. S. gelida, L.; New Zealand. Section of a spermogone: a, ostiole; 6, body of spermo- 
gone; c, thalline wart on which spermogone is seated. 
. Sterigmata and spermatia of same species. 
. Placodium circinatum, Pers., var. ecrustaceum, Nyl.; Hepp. exs., 407. Portion of plant, 
showing a, apothecia; 6, pseudo-lecidine large spermogones. 
. Section of the same apothecia a, and spermogones 6. 
. 22. 
. Squamaria ambigua, Wulf. Portion of thallus, showing minute, punctiform, immersed 
Sterigmata and spermatia of the same plant. 
spermogones a, and terminal soredia 6. 
. Placodium aureum ; Scher exs., 165. Thallus, bearing apothecia a, and papilleform sper- 
mogones 6. 
. Some of same spermogones magnified: a, orange-red ostioles, 
. Section of same spermogones. 
. P. elegans, DC.; Scher. exs., 338. Thallus, bearing apothecia a, and papilleform sper- — 
mogones 0. 
. One of the laciniz of same plant, magnified to show the same spermogones a. 
. Section of same spermogones. 
. Ephebe pubescens, Fr,; ex herb. Harriman. Sterigmata and spermatia. 

