3 o8 SYSTEMATIC 



Order II. LECIDEALES: Fam. GYALECTACEI, LECIDEACEI, UMBILICARI- 



ACEI and CLADONIACEI. 

 Order III. PARMELIALES: Fam. URCEOLARIACEI, PERTUSARIACEI, PAR- 



MELiACETy PHYSCIACEI, TELOSCHISTACEI and ACAROSPORACEI. 



Order IV. CYANOPHILI: Fam. LICHINACEI, EPHEBACEI, PANNARIACEI, 

 STICTACEI, PELTIGERACEI, COLLEMACEI and OMPHALARIACEI. 



The orders represent generally the principal phyla or groups, the families 

 subordinate parallel phyla within the orders. The first three orders are 

 stages of advance as regards fruit development ; the Cyanophili are a group 

 apart. 



Wainio 1 rendered great service to Phylogeny in his elaborate work on 

 Cladoniaceae, the most complicated of all the lichen phyla. He also drew 

 up a scheme of arrangement in his work on Brazil Lichens 2 . There is in 

 it some divergence from Reinke's arrangement, as he tends to give more 

 importance to the thallus than to fruit characters as a guide. He places, for 

 instance, Gyrophorei beside Parmelei and at a long distance from his Lecidei. 

 The Cyanophili group of families he has interpolated between Buelliae 

 (Physciaceae) and Lecideae. Many workers approve of Wainio's classifica- 

 tion but it presents some difficult problems. 



h. ZAHLBRUCKNER. The systematist of greatest weight in recent times 

 is A. Zahlbruckner, who is responsible for the systematic account of lichens 

 in Engler and Prantl's Natiirlichen Pflanzenfamilien. It is difficult to 

 express the very great service he has rendered to Lichenology, in that and 

 other world-wide studies of lichens. The sketch of lichen phylogeny as 

 given in the present volume owes a great deal to the sound and clear 

 guidance of his work, though his conclusions may not always have been 

 accepted. The classification in the Pflanzenfamilien is the one now gene- 

 rally followed. 



The class Liclienes is divided by Zahlbruckner 3 into two subclasses, 

 I. Ascolichens and II. Hymenolichens. He gives a third class, Gastero- 

 lichens 4 , but as it was founded on error 6 , it need not concern us here. The 

 Ascolichens are by far the more important. These are subdivided into: 



Series I. PYRENOCARPEAE, with perithecial fruits. 

 Series 2. GYMNOCARPEAE, with apothecial fruits. 



These are again broken up into families, and in the arrangement and 

 sequence of the families Zahlbruckner indicates his view of development 

 and relationship. They occur in the following order: 



1 Wainio 1887, '94, '97. 2 Wainio 1890. 3 Zahlbruckner 1907. 



4 Massee 1887. 5 Fischer 1890. 



