PYCNIDES OF CRUSTACEOUS LICHENS. 193 
The present category of polymorphism of spermatia and sterigmata includes in- 
stances of— 
(a) Different forms occurring in the same perithecium. 
Ex. Opegrapha varia, no. 1. 
(b) Segmentation or fission of the spermatia in the same individual, giving rise to 
two or three different sizes. "They are largest while attached, becoming divided 
subsequent to shedding from the sterigmata. 
Ez. Lecanora varia, no. 2. of L. lugubris" : Quart. Journal of Mi- 
Lecidea albo-atra, no. 1. croscopical Science, p. 9, pl. xi. figs. 9, 
disciformis, no. 4. 14, 15, 16.) 
Opegrapha vulgata, no. 13. Ex. Neuropogon melaxanthus, var. ciliatus. 
Arthonia astroidea, no. 3. (1st Mem. p. 117: Observations on New 
Lecidea lugubris. (* Structure Zealand Lichens, p. 527, pl. lxi. f. 27.*) 
(c) Spermatia that, in the same individual, are straight while attached, are curved ` 
when free. 
Ez. Lecanora sulphurea, nos. 1, 3. Ez. Lecidea parasema, no. 14. 
varia, no. 1. Opegrapha vulgata, nos. 4, 7. 
——— polytropa, no. 4. Verrucaria glabrata, no. 2. 
(d) Sterigmata are frequently simple and compound in the same individual. 
(e) Acquisition of colour by sterigmata—a concomitant apparently of age. 
Ez. Lecanora ventosa, no. 3. Ex. Arthonia cinereo-pruinosa, no. 1. 
Opegrapha vulgata, no. 8. 
(f) Acquisition of colour by spermatia. 
Ez. Opegrapha vulgata, no. 4. | | Ez. Graphis scripta, no. 2. 
2. Different forms or sizes of Basidia or Stylospores in the same species. 
Ez. Arthonia impolita. (“On Arthonia melaspermella,” p. 273, pl. vi. f. 7, 8.) 
When these differences are great and constant they may be referred, as in 
the case of spermogones, to different forms of pyenides, and to the category of 
plurality of organs. 
II. Pulrality. 
1. More than one form of Spermogone in the same species or individual. 
Ez. Pertusaria pustulata. Ez. Parmelia perforata. (1st Mem. pp.212,213.) 
Roccella Montagnei. (lst Mem. Lecanora subfusca, nos. 12, 15, 17. 
p. 140, pl. vi. f. 15-17.) varia, nos. 6, 9, 10. i 
Opegrapha vulgata. (“On Artho- polytropa, no. 3. 
nia melaspermella," p. 274.) cervina, no. 2. 
herpetica. Lecidea contigua, nos. 1, 3, 5, 10. 
Platysma ciliare. (lst Mem. p.181.) parasema, nos. 9, 11, 18. 
Ricasolia glomulifera. (lst Mem. albo-atra, no. 2. 
p. 204.) 
* Vide also Tulasne's Plate iv. f. 14. in his “ Mémoire." 
