Notes on Cephaleuros. 
BY 
N. THOMAS. 
With Plate LIX. 
HE group of organisms, a few of which form the subject of the present 
X communication, has from time to time been examined ,by various 
investigators. Kunze ( 7 ) in 1827 created the genus Cephaleuros for two 
epiphyllous Algae brought by Weigelt from Surinam. He gave as the 
characters of his genus : 
‘ Thallus orbicular, lobed, formed of filaments of radiating cells like 
those of Coleochaete or Melobesia, the lower surface furnished with 
rhizoids containing coloured protoplasm, and the edges armed with 
sharp hairs, and from the discs arise thick septated filaments terminated 
by a bunch of sporanges.’ 
In 1829 Fries ( 4 ) amplified Kunze’s description and compared 
CephaleiLros with the Lichen Strigula. 
Montagne (12), Kutzing (8), Mettenius ( 9 ), and Millardet ( 10 ) have 
described similar forms under various names ; Kutzing gave the name 
Phyllactidium arundinaceum to the species he investigated, and Millardet 
called the small yellow discs which he found on leaves of Abies pectinata, 
Phycopeltis epiphyton. De Toni ( 3 ) and other systematists down to 
Oltmanns ( 13 ) have discussed the position and interrelationships of these 
Algae, and many conflicting classifications have resulted, owing to the 
inadequacy of description of the organisms and the difficulty of comparing 
the various forms. 
Bornet ( 1 ) in 1873 described a Phyllactidium which is gradually 
invaded by Fungal hyphae, but which does not enter the composition of the 
Lichen until a comparatively late stage in development is reached. His 
figures and description, although incomplete, represent an Alga closely 
resembling the Ceylon forms of this investigation. It is of interest to note 
that, although there is no mention of it in the text, his Fig. 2 shows 
the curious loose end to the radial walls which is so remarkable a feature 
in the Ceylon material. 
[Annals of Botany, Vol. XXVII. No. CVIII. October, 1913.] 
