i37 



4- Section of thallus. 



5. Paraphyses and spore-sac with spores. 



•6. Spores; b, of B. parasema; a, common form in other species. 



7. Algae. 



10. Catillaria Ach. Meth. Lich. 33. 1803. 



In our territory Catillaria is represented by only one species, C. 

 grossa. Like most of the lower Lecidiaceae, this genus requires 

 further study. Tuckerman and others included it in the uncertain 

 group Hetcrothecium. Its general characters remind one strongly 

 of Lecidea ; the hypothecium is dark blue to black, the thecium 

 ■only faintly colored ; the apothecia are of medium size, disk flat- 

 tened, with slightly raised excipular margin ; the epithecium and 

 outer perithecium are black. 



The thallus is quite rudimentary in structure, being very thin, 

 smooth, somewhat scaly or paper-like ; no cortical tissue is present. 

 The hyphae of the thallus, as well as of the apothecium, are quite 

 brittle and rather short-celled. 



The algae occur in small groups and are doubtless Pleurococcus 

 vulgaris. The individual algal cells are considerably smaller than 

 those of Endocarfon, but otherwise similar. 



The genus is easily recognized by the distinctly two-celled, color- 

 less, rather large spores. The paraphyses are more slender and less 

 uniform in length than in Lecidea. Only a few representatives of 

 this genus are known. C. grossa occurs upon the bark of ash and 

 perhaps other trees. Since so little is known concerning this species 

 nothing definite can be stated concerning its range ; it is, perhaps, 

 eastern and northern. 



PLATE 2i. 

 Catillaria grossa .(Pers.) Blomb. 



1. Plants natural size. 



2. Section of apothecium. 



3. Section of thallus. 



a, dermal layer; b, algal layer; c, medullary layer. 



4. Spore-sac and paraphyses. 



5. Spores. 



6. Algae showing the tendency to arrange themselves in chains. 



11. Megalospora Meyen, Nov. Act. Acad. Leop. 19:228. 1843. 



In general appearance Megalospora closely resembles Catillaria. 



The apothecia are somewhat larger and disk more convex. The 



