ZYGODONTEI. 217 



OBDER XXI. ZYGODONTEI, Br. & Schimp. 



Sporangium striated, pyriform ; peristome none, single or 

 double ; veil hood-shaped, smooth. Mosses with the habit of 

 Gymnostomum. 



Differing principally from Orthotrichei in their smooth, 

 hood -shaped veil. 



69. ZYGODON, Hook. $ Tayl. 



Sporangium striate, apophysate, immersed or exserted ; 

 veil small, oblique, hood-shaped, smooth ; peristome none, 

 single or double, outer when present of thirty-two divisions 

 united two or four together, so as to make sixteen or eight 

 teeth ; inner sixteen or eight cilia alternating with the teeth 

 of the outer peristome. Perennial tufted Mosses, with punctate 

 leaves and plane, not revolute margins. 



1. Stem tall, sporangium cylindrical. 



1 . Z. Forsteri, Wils. ; monoicous ; stems densely tufted ; 

 leaves erecto- patent, acuminato-spathulate, hyaline below; 

 sporangium pyriform, long-necked, striate ; lid with a curved 

 beak ; outer teeth strongly recurved when dry. Hook. $ 

 Wils. t. xlvi. ; Eng. Bot. t. 2225. 



Trunks of trees. South of England. Rare. Bearing fruit 

 in spring. 



Forming dense, succulent, green tufts. Stems matted with 

 whitish rootlets; leaves dark -green above, pale towards the 

 base, then red ; outer teeth eight, yellowish ; cilia hyaline, a 

 little shorter. 



2. Z. conoideus, Hook, fy Tayl. ; dioicous ; loosely tufted ; 

 leaves spreading, curved upwards, lineari-lanceolate, acumi- 

 nate ; nerve ceasing near the tip ; sporangium oblongo-pyri- 

 form, striate ; lid with a long beak ; outer teeth trun- 



