ISOTHECII. 145 



£ inch high, even ; sporangium small, with a distinct barren 

 base ; lid short, conical ; inner peristome pale. 



The generic name is intended to express the resemblance of 

 the branches to a slender mouse-tail. The genus differs from 

 Leskea in the reticulation. 



20. PLATYDICTYA, Berk. 



Sporangium erect, symmetrical, at length turbinate ; peri- 

 stome double, inner with or without intermediate cilia ; leaf- 

 cells large, nearly equal throughout ; stem hair-like, confer- 

 void. 



1. P. Sprucei, Berk.; stem very delicate, ascending or 

 creeping ; branches and branchlets few ; leaves distant, erecto- 

 patent, narrowly ovate, acuminate, nerveless, nearly entire ; 

 sporangium erect, elliptic or turbinate; lid conical, acute. — 

 Hook. # Wils. t. liv. 



On shady subalpine rocks. North of England. Bearing 

 ripe fruit in summer. 



Dioicous; forming very short, thick tufts, with hair-like 

 stems and branches; leaves distant, spreading, ovato-lanceolate, 

 strongly acuminate, obscurely toothed above, nerveless, pellu- 

 cid; cells large, nearly equal throughout; fruitstalk i inch 

 long ; sporangium obovate, turbinate and wide-mouthed when 

 dry ; lid conical, acute ; inner peristome with occasionally a 

 few intermediate cilia. 



I do not see how this Moss can be associated with Schimper's 

 Amblystegium, still less with true Leskea. Its large uniform 

 cells, erect sporangium, and imperfect inner peristome, all se-' 

 parate it widely from Amblystegium. As I know of no other 

 genus in which it can be placed, I am forced to propose a new 

 one for its reception. 



