FAMILIES AND GENERA 319 



XIV. Pyrenidiaceae 

 The only family of Pyrenocarpineae associated with blue-green algae. 

 The genera of Pyrenidiaceae are all monotypic, only one is common and 

 of wide distribution, Coriscium {Normandina Nyl.). Pyretiidium is the only 

 member that has a fruticose thallus, and that is of minute dimensions. 

 Eolichen Heppii, found and described by Zukal, is a doubtful lichen. " Lopho- 

 thelium" Stirton is a case of parasitism of a fungus, Ticothecium, on the 

 squamules of Stereocaulon condensatum. 



Algal cells Scytonenia or Stigonema. 



Thallus crustaceous'; spores simple, colourless i. *Rhabdopsora Miill.-Arg. 



Thallus crustaceous ; spores l-septate, colourless 2. *Eolichen Zuk. 



Thallus crustaceous ; spores muriform, brown 3. *Pyrenothrix Riddle^. 



Thallus squamulose ; spores numerous, simple 4. *Placothelium Miill.-Arg-. 



Algal cells Nostoc. 

 Thallus crustaceous; spores filiform, simple, colourless 5. *Hassea A. Zahlbr. 

 Thallus fruticose ; spores elongate, 3-septate, brown ...6. Pyrenidium Nyl. 



Algal cells Microcystis (Polycoccus). 

 Thallus squamulose ; fructification unknown 7. Coriscium Wainio. 



Series II. GYMNOCARPEAE 

 SuBSERiES I. Coniocarpineae 



This small subseries is marked by the peculiar "mazaedium" type of 

 fruit with its disappearing asci. It forms a connecting link between the 

 families with perithecia and those with apothecia. The thallus is crustaceous 

 or fruticose, often poorly developed and sometimes absent. The algal cells 

 are Protococcaceae or rarely Trentepohlia. 



XV. Caliceaceae 

 The thallus is thinly crustaceous, sometimes brightly coloured, some- 

 times absent, taking no part in the formation of the fruits; these have 

 upright stalks with a small capitulum, and often look like minute nails. 

 One genus, Sphinctriiia, is parasitic on the thallus of other lichens, mostly 

 Pertusariae. 



Fruits with slender stalks. 

 Spores simple. 



Spores colourless i. Coniocybe Ach. 



Spores brown 2. Chaenotheca Th. Fr. 



Spores septate, brown. 



Spores i-septate 3. Calicium De Not. 



Spores 3-7-septate 4- Stenocybe Nyl. 



Fruits with short thick stalks. 



Spores globose, brown (parasitic) 5. Sphinctrina Fries. 



Spores I -septate, brown 6. *Pyrgidium Nyl. 



1 Zahlbr., m Hedwigia, Lix. p. 301, 1917. ^ Riddle 1917. 



