265 



Fig. 47. 

 Ricasolia amplissiona Leight. — a. Yertical section of a young apotlieciuiu. x30. 

 h. A theca and paraphysis, X •"^50. c. Spores, X 500. d. Vertical section of 

 a spermogone, X 30. c. Jointed sterigmata and spermatia, X TiOO. 



species occur in the more humid tracts of our islands. The tribe ha.< 

 been divided by Nylander into the followiDtr '2 snbtribes, comprisintr 

 o genera, founded upon differences in the structure and character of the 

 thallus, the presence or absence of cyphellse, and the nature of the apo- 

 thecia. 



Subtribe I. STICTINEI Xyl. Flora, 1879, p. 360. 



Thalliis either cyphellate or ecyphellate beneath ; gonidial layer 

 consisting of gonimia arranged in phiri-locnlar nodules. Apothecia 

 lecanoroid, rarely parmeleine. 



Distinguished by the nature of the gonidial layer, -which separates it 

 as a very distinct subtribe. The plants are easily recognized by this 

 layer presenting under the lens, or even to the naked eye, a bluish or 

 leaden-bluish appearance. 



44. STICTINA Nyl. Flora, 1860, p. 66, Syn. i. p. 333.— Thallus 

 variously lobate or laeiniate, often sorediiferoiis ; beneath cyphellate 

 or pseudocyphellate, with simple rhizinaj (rJiizohi/pJice'Syl.) ; gonimia 

 often 2-3 moniliform, Apothecia usually with septate spores, 

 Spermogones innate, not prominent, with spermatia somewhat short, 

 obtusely and slightly thickened at either aj^ex. 



