Ill 



been classed as fungi by different authors, notably by Rehm, who 

 has included Calicium, Coniocybe, Cyphelium, Sphinctrina, and 

 Acolium under his division Calicieae of the Ascomycetes. 



There is one character which distinguishes this group from all 

 others, and that is the peculiar manner in which the spores are 

 enabled to escape from the spore-sacs. The wall of the spore-sac 

 begins to gelatinize near the apex ; finally the greater portion of the 

 wall is dissolved, liberating the immature spores ; the spores remain 

 in the space between the thecium and exciple until they are mature ; 

 they increase in size, the loose unevenly thickened exosporium 

 enlarges and becomes dark or blue-black ; they take up the re- 

 quired food substances by absorption from the enclosing tissues and 

 the gelatinous imbedding material consisting principally of the gela- 

 tinized spore-sacs. When the spores reach maturity the exciple or 

 apothecial covering opens by an apical pore which varies greatly in 

 size. Distribution of the spores is brought about by the wind either 

 directly or by its action upon the slender stipes. 



The symbiotic alga is Cystococcus humicola Nag. (except in 

 Coniocybe) ; it differs somewhat from the same form occurring in 

 the higher lichens in its smaller size and less intimate association 

 with the haustorial branches of the hyphae. 



The genetic series Mycocalicimn, Coniocybe, Calicium, Cyphelium, 

 and Acolium is perfect, but there is a wide gap between Acolium and 

 Sphaerophorus, the intervening generic links not being represented 

 in the territory. The limitations of genera and species of the lower 

 types are very uncertain, and this is particularly true of the Ameri- 

 can forms. In general the lower representatives of the family are in 

 need of careful study and revision. 



Key to the Genera. 



Apothecia borne on slender stipes ; . plants small. 



Thallus crustaceoufe, usually wanting ; spores dark. I. Mycocalicium. 

 ■ Thallus crustaceous, always present. 



Spores simple, colorless. 2. Coniocybe. 



Spores two-celled, dark. " 3. Calicium. 



Spores simple, dark. 4- Cyphelium. 



Apothecia nearly sessile ; thallus crustaceous. 5. Acolium. 



Apothecia terminal on a large rigid branching fruticose thallus. 



6. Sphaerophorus. 



