50 
complete to warrant us in making any such attempt. Addi- 
tions are daily being made to their number, and the relation 
they bear to the structures on which they grow is becoming 
better understood. All that is at present aimed at is to 
arrange them in a group under the most recent names given 
them by systematists ; so that, by exhibiting the confusion 
which exists regarding their place in classification, some 
inducement may be held forth to study them more carefully 
than hitherto. 
The parasites at present classed under Lecidea may be con- 
veniently grouped according to the character of the spores as 
follows : 
a. Spores usually simple and colourless. 
Species 1. Lecidea vitellinaria, Nyl. 
Synonyms. Lecidella, Korb., Parerga, p. 459 ; 
Leiglit., Exs., No. 182. 
Lecidea Pitensis, Lonnr. 
On thallus of Lecanora vitellina, both saxicolous and 
terricolous forms (Nyl., Prod., 126 ; Mudd, 212; Th. Fries, 
Arct., 222). Spores 8, ellipsoid or subspherical. Nylander 
suggests that it may be regarded as an athalline form of 
Lecidea parasema, an opinion in which I quite concur. 
2. L.inquinans, Tul., Mem., 117. Nyl., Syn., 179 ; Lindsay, 
Monograph of Abrothallus, 6. 
Syn. Abrothallus , Tul. 
Nesolechia, Korb. 
Lecidea argillacea, Korb., Syst., 255, Parerg. 
462 ; which, however, is described as usually 
having a thallus, and when athalline as occur- 
ring on that of Verrucaria epigaea, Acli. 
L. parasitica, pr. p. Tul., 117, the spores of 
which at once separate it. 
On the sterile thallus of Bceomyces rufus and B. roseus 
(Nyl., Prod., 145 ; Syn., 179) ; or of Lecidea decolorans 
(Tul., 117). 
Spores 4-8, ellipsoid or oblong. Tulasne says he has in 
vain searched for pycnidia. Nylander (Prod., 145) places 
this Lichen and Abrothallus oxysporus in his section Epithallia 
of the genus Lecidea, and in his ‘ Enumeration generale’ (127) 
he includes L. oxysporella ; while Stizenberger ( £ Beitrag zur 
Flechten-systematik,’ 162) apparently arranges under Epi- 
thallia the genera Phacopsis and Nesolechia. It is, at least, 
most arbitrary and unscientific to place Lichens so closely allied 
as L. inquinans, L. oxyspora and L. oxysporella in separate 
genera or subgenera ! 
3. L oxysporella, Nyl., Prod., 145. 
