ENDOCARPON. 



291 



nute, brownish-black. There are two marked varieties, var. 

 timbilicatum, which is umbilicate, lobed, simple or polyphyl- 

 lous ; and var. complicatum, which is csespitose and imbri- 

 cate-lobate, with ascending lobes. (E. B. 593.) 



Common in lowland and subalpine districts, on moist 

 rocks in the neighbourhood of waterfalls or rivers, or which 

 are frequently covered by water. We have found it, by 

 the side of the Tay, on boulders frequently covered by the 

 river when flooded, and on the craggy southern face of 

 Kinnoull Hill, near Perth. When under water it has a 

 deep olive-colour. It sometimes attains a diameter of seve- 

 ral inches : we have seen large specimens from the island of 

 Mull. Its spores are ellipsoid, double- walled (margined), 

 pale. Its spermogones are immersed, and indicate their 

 presence by circular, brown, flattened or centrally depressed 

 spots towards the periphery of the thallus. They are ostio- 

 late ; they exceed in depth the thickness of the thallus, and 

 thereby produce on its under surface, as the apothecia also 

 do, a papulose roughness ; and they consist of a very dense, 

 grey or rose-coloured tissue. The sterigmata are articulated 

 and ramose ; the spermatia straight. 



Thallus squamulose, adherent by whole surface. 



2. Endocarpon Smaragdtjlum {smaragdus, the emerald). 



