18 {17) Perithecia usually immersed, ostiole border frequently raised, spores 9-12 x 5-6/im; juga rarely limited to borders of 



areoles, usually scattered within areoles (Fig. 33); thallus more translucent wet than dry Verrucaria degelii 



Figure 33.— a. Vertical section of 

 perilheciuni. Scale is 0.1 mm. b. 

 Thallus of Verrucaria degelii. 

 Scale is 1 mm. 



18 (77) Perithecia elevated, often craterous. juga forming a reticulate pattern (Fig. 34); thallus opaque dp,', translucent wet 



Verrucaria amphibia 



Figure 34.— a. Vertical section of perithecium. Scale is 1 mm. b. Thallus of Ver- 

 rucaria amphibia. (Specimen illustrated is thicker and stored longer than that in 

 Fig. 39b.) Scale is 1 mm. 



19 (17) Juga appearing as pegs prottuding from thallus and also to some extent on penthecia; thallus nmose-areolate. 

 usually blackish-brown and opaque (wet or dry); perithecia often large, 0.3-0.7 mm diameter, immersed or 

 elevated, gently sloped to nsing abruptly, sometimes depressed on top (Fig. 35); spores 10-20 x 7-lOfim Verrucaria maura 



Figure 35.— a. Vertical sections of perithecium. Scale is 0.1 

 mm. b. Thallus i>f Verrucaria maura. Scale is 1 mm. 



12 



