MOSSES WITH A HAND-LENS 



159 



I 



thallus varies from 1-3 inches in length and also has purple 

 margins and purple scales underneath. There are abundant 

 raised pores all over the surface. The perianth is inconspicuous 

 and on the upper surface of the female receptacles are ribs alter- 

 nating with the lobes (four or less). The peduncle is at first 

 covered with hairs which mostly disappear except at base and 

 apex. The spores are mature in early spring. This species is 

 perhaps most likely to be mistaken for Marchantia because of its 

 large size and stalked male discs. 



GRIMALDIA. 



G. FRAGRANS (Balb.) Corda (G. 

 sessilis Sulliv.) is distinguished by 

 the peduncle, hairy at base and apex; 

 female receptacle without alternating 

 ribs, and antheridia in a disk im- 

 mersed in the apex of the thallus. The 

 thallus also has purple margins and 

 purple scales. Its spores mature in 

 May, but in the autumn the spots from 

 which the female stalk and receptacle 



develop are densely covered with 



FIGURE 84. Grimaldia i j i , ,- 



fragrans (After Bischoff.) slender whlte SCaleS " **8 a 

 part of male and female whitish spot visible for several feet. 

 plants; section of male disk; In Reboulia the scales are much 

 female receptacle, etc. f ewer an( J are more like hairg 



FIGURE 85. Reboulia 

 hemisphaerica (After Bis- 

 choff.) 



REBOULIA. 



R. HEMISPHAERICA (L.) Raddi. 

 This species resembles Preissia in 

 size and appearance, but is distin- 

 guished by its very small stomata, 

 two toothed purple scales, and sessile 

 dusky purple male receptacles. The 

 spores mature in late autumn. 



Like Grimaldia the thallus of 

 Reboulia bears a number of white 

 slender scales in autumn around the 



