TETRAPHIDEI. 215 



1. B. aphylla, Hall. ; stem obsolete ; lower leaves roundish, 

 deeply toothed, upper fringed ; sporangium plano-convex ; 

 outer processes irregular, thick, and cellular. — Hook, fy Wils. 

 t. xxii. ,• Eng. Bot. 1. 1596. ; (Plate 19, fig. 6) ; Moug. 8f Nest. 

 n. 38. 



In woods and heaths. Rare. Scotland, Yorkshire, and 

 Norfolk. It has been lately found in unusual abundance by 

 Mr. Coutts near Aberdeen. Bearing fruit in May. 



Dioicous, scattered. Stem a little bulb with minute hair- 

 like leaves j vaginula ovate, fleshy ; fruitstalk scabrous, an 

 inch or more long '; sporangium reddish-brown ; spore-sac 

 attached to its walls by threads ; lid conical, obtuse. 



The other European species occurs on decayed wood, and 

 has never been found in this country ; its outer teeth are more 

 regular. The question whether these should be called an outer 

 peristome or not, is one of great difficulty ; but we believe 

 Mr. Wilson's view is the right one. It should be observed 

 that the teeth of Polytrichiei consist of several layers, and that 

 these are disunited in Dawsonia. Schimper now considers 

 the outer layers to represent the annulus, and between these 

 and the inner plicate peristome, an outer delicate peristome to 

 exist, more or less agglutinate with the annulus, and exceeding 

 it. The part commonly called the annulus is merely the 

 jagged edge of the sporangium. 



Obdee XX. TETRAPHIDEI, Br. & Schimp. 



Sporangium erect ; veil mitriform, plicate ; peristome united 

 with the top of the columella which is divided into four pyra- 

 midal irregularly reticulated teeth. 



67. TETRODONTITJM, Schwceg. 

 Monoicons. Sporangium oval-oblong, regular; veil sub- 



