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POPULAR HISTORY OF LICHENS. 



Genus II. SAGEDIA, Fries. 



Gen. Char. Thallus subcrustaceous ; apotliecia immersed, 

 globose, becoming attenuated at the apex into a narrow neck, 

 opening by a dilated ostiole on the surface of the thallus.* 

 (Name probably from crdyrj, a peculiar kind of shield, and cTSos, 

 like, in allusion to the form of the fructification.) 



This genus is intermediate in characters between Endo- 

 carpon and Verrucaria. It agrees with the former in having 

 an immersed apothecium, with a gelatinous deliquescent tha- 

 lamium, but it differs in the necked ostiole ; while it resem- 

 bles the latter in the character of the thallus, but differs in 

 having no carbonaceous perithecium, in its necked ostiole, 

 and in the wholly immersed thalamium. 



1. Sagedia cinekea. Thallus membranaceous, squamu- 

 lose, closely adnate, — above greyish-pruinose, — below black- 

 ish-spongy; squamules discrete, or aggregated into a con- 

 tiguous crust somewhat foliaceous at circumference. Ostioles 

 protuberant, spheroidal, black. 



On the ground or rocks on the summit of Ben Lawers, 

 Perthshire, and on the island of Stronsay, Orkney. Its 

 spores are narrow-oblong, uniseptate, pale. (E. B. 2013). 



2. Sagedia aggregata {aggrego, to gather together). 



* On Sagedia, Fr., and allied genera, f Botanische Zeitung,' Feb. 23, 1855. 



