MOSSES WITH A HAND-LENS 



157 



appearance, but the surface of 

 Marchantia is marked off into 

 diamond shaped areas, called areo- 

 lae, with a stoma in the center of 

 each, while in Conocephalum the 

 areolae are larger, and hexagonal 

 in the center of the thallus to 

 oblong-hexagonal on the margin, 

 with the stoma so large as to 

 be visible to the naked eye. Re- 

 ceptacles which bear the capsules 

 are very different also as is shown 

 by the figures. The capsules of 

 Conocephalum mature in April, those of Marchantia in June and 

 July. The stalked receptacles may assume their characteristic 

 form much earlier. 



FIGURE 80. Conocephalum 

 conicum (After Bischeff.) 



FIGURE 81. Lunularia 

 cruciata (After Bischoff.) 



LUNULARIA. 



L. CRUCIATA (L.) Dum. Any 

 one who has ever had to do with 

 green houses must have noted the 

 beautiful green thalli of this plant. 

 Small plants are sometimes mistaken 

 for large fern prothallia, but the 

 crescent shaped receptacles filled 

 with gemmae are abundant on all the 

 larger plants and render them easy 

 of recognition. This plant is in- 

 troduced from Europe and has but 

 once been reported as fruiting in 

 this country. (Bryologist, Sept., 

 1902.) 



ASTERELLA. 



A. TENELLA (L.) P. de Beauv. (Fimbriaria tenella Nees.) is 

 fairly common on damp earth. The sterile fronds are often 

 dichotomously branched and reach nearly an inch in length. The 

 thallus is purple on the margins and has purple scales under- 



