Lichens

by Annie Lorrain Smith

Fam. Tetrasporaceae. Cells in groups of 2 or 4 surrounded by a gelatinous sheath.

1. Palmella Lyngb. Cells globose, oblong or ellipsoid, grouped without order in a formless mucilage ([Fig. 27]). Among lichens associated with Palmella are the Epigloeaceae and Chrysothricaceae.

Fig. 26. Urococcus sp. Group of cells much magnified (after Hassall).

Fig. 27. Palmella sp. × 400 (after Comère).

Fig. 28. Gloeocystis sp. × 400 (after Comère).

2. Gloeocystis Naeg. Cells oblong or globose with a lamellate sheath forming small colonies; colour, red-brown ([Fig. 28]). This alga along with Urococcus was found by Hue in the cephalodia of Lepolichen coccophora, but whereas Gloeocystis frequently occupies the cephalodium alone, Urococcus is always accompanied by Scytonema, the normal gonidium of the cephalodium.