464 TRANSACTION'S LIVERPOOL BIOLOGICAL SOCIETY. 



it lias nothing whatever to do with the pollen grain. 

 The forms and varieties mentioned here and there 

 in the literature are of no special value. 



Diagnosis : 



Thallus, consisting of root and shoot. Root, a flat, hard, 

 reddish disc of irregular outline, made up of very 

 regularly arranged ^cells of very uniform size and shape. 

 Shoot, upright, 15-17cm. high ; narrow or slightly 

 flattened stalk ; frond repeatedly forked and divided into 

 very much flattened and thin lobes ; internal conducting 

 cells elongated, loose, hyphal in younger parts ; more 

 external and small collecting cells leading into external 

 rows of assimilating cells, each containing one rhodo- 

 plastid. 



Nemathecia, slightly prominent dark red spots on young 

 lobes ; sporangia in rows ; tetraspores roundish, formed by 

 cruciate division ; mature December to March ; in ger- 

 mination the spores divide into a number of cells before 

 increasing in bulk. 



Spermophores, small, narrow, white leaves on apical 

 margins of frond ; antheridia formed by two or three 

 outer cells of assimilating layer ; spermatangia produce 

 one spermatium each. Mature October to December. 



Carpophores, small leaflets on frond ; procarpia just 

 inside assimilating layer ; basal cell, cutting off auxiliary 

 cell before fertilisation, two intermediate cells, carpo- 

 gonium and trichogyne ; sporogenous hypha of egg cell 

 fuses with cytoplasm of auxiliary cell, and numerous 

 sporogenous hypha? grow out towards the central staroh- 

 laden cells of the carpophore, fusing with them and pro- 

 ducing carpospores ; cystoearps forming prominent dark 

 red patches on the frond ; 'carpospores roundish. Mature 

 December to March. 



