Oscillator iacece 



331 



water. In some instances there is a deposition of lime in the 

 stratum. The filaments are either simple or variously branched, 

 and are sometimes of great length. The sheaths are firm and 

 lamellose, generally attenuated towards the apex, and rarely 

 colourless. The inner layers of the sheath may be any shade 

 of yellow, yellow-brown, purple, or blue, and they are usually of 

 a deeper colour than the outer layers. There are relatively few 

 trichomes (sometimes not more than two) within each sheath, laxly 

 disposed, and sometimes spirally twisted. 



Fig. 151. A, Schizothrix Miillerii Nag., from Penyghent, W. Yorks. B, S. lardacea 

 (Ces.) Gom., from Arncliffe, W. Yorks. C, Dast/(jlcea amorpha Berk, (a small 

 form) from Thursley Common, Surrey. (All x 460.) 



The largest British species is S. Miillerii Nag. (thickness of trichomes 

 7 13 n ; fig. 151 A) and the smallest is S. delicatissima W. & G. S. West 

 (thickness of trichomes 0'6 0'8/i). S. calcicola (Ag.) Gom. and S. lardacea 

 (Ces.) Gom. (fig. 151 B) are not infrequent on wet rocks. In S. funalis W. & 



