come to my notice. The apothecia being small, dark and scattered, 

 makes it difficult for the collector to find specimens. 



As with Mycocalicium it is questionable whether this genus should 

 be included among lichens ; some authors include BiatorcUa in Bia- 

 tora. 



PLATE 15, fig. 2. 



BlATORELLA GEOPHANA (Nyl.). 



Spore-sac with spores and paraphyses. For the general structure of 

 apothecia and thallus see Plate 17. 



2. BIATORINA Mass. Mem. Lich. 134. 1853. 



The representatives of this genus are recognized by the two- 

 celled, colorless, spindle-shaped spores. The thallus is rudimentary 

 but readily recognizable ; it is uniformly crustaceous, of a greenish 

 color, and never becomes areolate or warty in any of the species 

 examined. The algae are constantly Chroole-pus umbrina. The 

 much-branched chains consist of rather small cells in which the 

 yellowish brown inclusions are quite distinct. The algal cells are 

 closely entwined by the much-branched haustoria. In some cases 

 the haustoria penetrate the algal wall (endotrophic haustoria). The 

 hyphal cells are slender, much-branched and much-contorted. 



The apothecia vary from small to very small, outline well-marked, 

 somewhat cup-shaped ; the hypothecium is colorless, and the epithe- 

 cium yellowish to pale brown, which in connection with the spore- 

 characters makes the recognition of the species easy. 



According to some authors this genus should be included in 

 Gyahcta from which it is, however, readily distinguished by the 

 spore-characters as well as by those of the apothecium. 



Its representatives, which seem to be few in the territory, occur 

 upon soil and tree-trunks {B. -pineti), more commonly upon the 

 gametophytic generation of mosses, in which case the thallus is very 

 'deficient. 



PLATE 1 6. 

 BIATORINA PINETI (Tuck.). 



1 . Plants normal size upon a piece of bark ; a, apothecia. 



2. Fragment of bark with plants magnified; a, mature apothecia ; b, im- 



mature apothecia. 



