A HISTORY OF DURHAM 



of the Tees plunge over an immense cliff of basalt. This is the home 

 of Zygodon lapponicus in the fissures of the rocks, of the very rare and 

 delicate Bryum concinnatuvi^ of 'Tetraphis Broivniatia on the underside of 

 stones, and again of Catoscopium nigritum. 



Returning from Cauldron Snout over the flat top of Widdy Bank 

 we reach a small pool supporting an exceedingly large form of Hypnum 

 giganteum associated v^^ith the equally fine Hypnum revolvens var. Cossoni 

 iovravifalcata. 



We now reach Langdon Beck, and among the calcareous drift of 

 this river valley is the very rare and minute moss Amblyshghwi Sprucei. 

 Other rare mosses occur in this valley. On the top of the road into 

 Weardale is a small bog supporting two rare plants, the bog moss Sphag- 

 num Gravetii, and the Harpidium, Hypnum exannulatum var. purpurascens. 



Descending the Weardale road we reach Ireshope Burn, containing 

 many mosses, the chief being the minute Seligeria Doniana, and Seligeria 

 pusilla growing on its limestone clints, and Hypnum filicinum var. gracilescens, 

 Wcisia rupestris var. intermedia, and Eurhynchium pumilum close by. In a 

 pool near this burn float large masses of Hypnum exannulatum var. steno- 

 phyllum. 



Our next stream, Burnhope Burn, is of particular interest to the 

 bryologist. At its side in a spring is Philonotis adpressa in fruit, the only 

 place in England for this. Deeply imbedded in the gravelly drift of its 

 bank are Dichodontium pellucidum vars. compactum and fagimontanum, and 

 IVeisia viridula var. densifolia. On the large boulders in the upper part 

 of the stream are huge masses of Hypnum ochraceutn, and on the walls 

 near it is an abundance of Barbula recurvifolia. By the side of Kilhope 

 Burn are the rare mosses JVeisia crispata, Bryum palkscens, Amblystegium 

 Juratzlianum and Hypnum jiuitans var. ovale. Ascending the Kilhope 

 road to the top of Burnhope Seat, we again meet with Cylindrothecium 

 concinnum, and on the top of the Seat is a massive growth of Hypnum 

 Jiuitans vav.falcatum fruiting by a pool. 



Weardale is remarkable for the abundance of fruit on the mosses. 

 Bryum pallcns and Philo?iotis fontana are crowded with fruit on the 

 gravelly drift by the burns. On the side of Sedling Burn is a huge mass 

 of boulder clay covered with a brown carpet of capsules of a very tall 

 and compact growth of Philonotis fontana, associated with a very tall and 

 compact growth of Dicranella varia. 



LIST OF MOSSES 

 Sphairnum fimbrintiim, Wils. Spliagnum Russowii, Warnst. {continued) 



— Giigciisolinii, Russ. var. viresccns, Russ. 



var. commune, Russ. — Warnstorfii, Russ. 

 „ cristatum, Russ. var. purpur.iscens, Russ. 



„ hygropliilum, Russ. „ versicolor, Russ. 



„ stacliyodcs, Russ. „ viridc, Russ. 



„ xerophilum, Russ. — rubcllum, Wils. 



— Russowii, Warnst. var. flavum, C. Jens. 



var. flavcsccns, Russ. „ pallcsccns, Warnst. 



„ poecilum, Russ. „ ]iur|nnascens, Warnst. 



„ rliodotlirouni, liuss. „ rubnini, Giav. 



64 



