-3^ 



upon a stalk one and one-half or two inches long. The stalk is rather fleshy, 

 and arises from a concave disk at the fork of the thallus. The receptacle is con- 

 vex, obtuse at the apex, and is cut into six short lobes. Beneath these lobes are 

 the involucres and their capsules, which resemble somewhat those of Marchan- 

 tia. This species also is dioecious, and has bispiral elaters. It should be col- 

 lected about the first week in April. 



EXPL.\NATI0N OF FIGURES. 



Fig. I. Male plant of Marchantia polyuiorpha reduced. 



Fig. 2. Section of male receptacle of M. magnified; a, a, a, antheridia. 



Fig. 3. Female plant of M. reduced. 



Fig. 4. Section of part of female receptacle of M. po/yjiiorfiha magnified; 

 s, sporogonia.one not yet emerged from perianth. The outer fringe represents 

 the involucre. 



Fig. 5. Portion of elater of M. po/ymorpha, showing spiral bands, magnified 

 greatly. 



Fig. 6. Sterile thallus with gemmae. 



Fig. 7. Cells of thallus, with stomata magnified: a. Marchantia; b. Cono- 

 cephalum. 



Fig. 8. Thallus of Conocephaltnn conicum with female receptacles, reduced. 



LICHENS— ALECTORIA, EVERNIA, RAMALINA. 



Bv Carolyn W. Harris. 

 [With Plate IV.) 



In this second article on lichens, Atectoria, Evernia and Ramalina will be 

 considered. They belong to the same family as the Usneas, the i'sneei. 



In walking along country roads, you 

 no doubt have noticed, on old fences or 

 dead trees, little tufts of "black hair." 

 These are Alectorias. The thallus is 

 fruticose, rather rigid and short, again 

 soft and pendulous. At the joints it is 

 flattened, for the medullary cord is not 

 solid like that of Usnea, but is soft and 

 web-like ; the flattening at the joints gives 

 Fig. I. Alectoriajubatavar. greater strength and tenacity to the 



iniplexa x i. thallus. Except in color, Alectoria re- 



sembles [Jsnea. It is not the gray-green 

 of the latter, but varies from light brown to almost black. In only one species 

 is it at all green. The surface* has a smooth, shiny appearance, as though it had 

 been varnished. The apothecia are small and sessile ; they are not surrounded 

 by fine fibrils as in Usnea. They are usually the same color as the thallus, and 

 have the same shiny appearance. 



The most common form of the genus is Alectoria jubata L. \ ar. chaly- 



The magnification of figures 2 and 4 is twice too great, as figures were reduced J^. 



1^556 



■u 



