356 
III. The same host ( Lichen-thallus ) frequently bears more 
than one Parasite. 
This assertion will be further borne out when my list of 
Micro-Fungi parasitic on Lichens is published. Meanwhile 
the subjoined list will illustrate the frequency with which 
Micro-Lichens occur on the thallus of higher species. On — 
Sticta Sylvatica ) Abrothallus Smithii ; A. Wel- 
S. fuliginosa j witzschii. 
Parhelia sinuosa ) , „ ,, 
T1 t A. Smithii ; A. oxysporus. 
P. conspersa j > j r 
Parhelia saxatilis : — Abrothallus Smithii ; A. oxy- 
sporus ; Sphinctrina turbinata ; Lecidea Egedeana. 
P. caperata : — A. Smithii; A. microspermus ; A. 
oxysporus ; Nesolechia thallicola. 
P. perforata: — Abrothallus Curreyi; Microthelia 
Cargilliana. 
Piiysica parietina : — Lecidea glaucomaria ; Celi- 
dium varium ; Arthonia varians. 
P. pulyerulenta : — Karschia pulverulenta ; Abro- 
thallus Smithii. 
P. obscura : — Lecidea obscuroides ; Buellia convexa. 
Cetraria glauca : — Abrothallus Smithii; A. oxy- 
sporus. 
C. Islandica : — Abrothallus Smithii ; Lecidea Cetra- 
ricola. 
Peltidea can in a : — Celidium fusco-purpureum ; Scu- 
tula Wallrothii. 
Solorina crocea : — Biatorina tuberculosa ; Khaga- 
dostoma corrugalum ; Microthelia Solorinaria. 
S. saccata: — Scutula Krempelhuberi ; Xenosphceria 
Engeliana. 
Usnea barbata: — Abrothallus Usnece ; A. Smithii; 
Phymatopsis dubia. 
Evernia prunastri : — Abrothallus Smithii ; Micro- 
thelia prunastria. 
Stereocaulon tohentoslm: — Biatorina Stereocau- 
lorum ; Scutula Stereocaulorum ; Ephebe pubes- 
cens. 
ILeomyces rufus : — Nesolechia ericetorum ; Thelo- 
carpon epithallinum ; Lecidea parasitica, scabrosa, 
inquinans, arenicola. 
B. placopiiyllus : — Lecidea scabrosa ; Lahmia Fuis- 
tingii. 
