(2145 
differences, dont les plus importantes se rapportent a@ la dimension et au 
nombre.’ (Suppl. p. 50). But Nylander’s description of the spores of 
C. seriale, from Acharius’s specimen (Nyl. in Prodr. Fl. N. Gran. p. 110, 
n.) varies inimportant respects from that given by Fée (Suppl. p. 50, t. 40) 
and adds another to the already noted interesting features of this lichen. ! 
Cuban specimens, collected by Mr. Wright, and agreeing entirely with 
Nylander’s plant in Lindig’s collection (Herb. N. Gran. coll. 2, n. 33) offer 
oblong-ovoid, or more rarely oblong, quadrilocular spores, without the 
colour, but with the spore-cells of Glyphis labyrinthica, and of the ernce- 
form type; of which the spores of the species last named are a reduced 
expression. Nor is this apparent divergence in the direction of the 
coloured series, the only one. In Montagne'’s description of his C. lactesm 
(Pl. Cell. Cub. p. 161) we find ‘asci breves obovati sporidia 5-6 oblonga 
intus graniuosa (immatura ?) continentes, which readily suggests the 
doubt whether riper specimens might not offer the muriform structure. 
And, in fact, in original specimens of his lichen given to me by the friendly 
author, I find, in obovate or saccate thekes, oblong-ovoid or also oblong, 
colourless or scarcely coloured, muriform-multilocular spores; very com- 
monly resembling the similarly smallish spores of C. seriale, except that 
here, instead of four sporoblasts, we have six to ten transverse series, 
and two to four longitudinal ones. It is evident then that if Chiodecton 
is comparable with Opegrapha, as regards the predominant type expressed 
in its spores, it is comparable with it also in its anomalies. 2 
Twenty-three species of this genus are reckoned in the various publi- 
cations of Dr. Nylander; and, adding C. wmbratum, Fée, and C. Jfon- 
tagne?, the number of distinguishable forms may be called twenty-five. 
Two of these belong to the European Flora; one of them being found on 
rocks at Cherbourg in Normandy, and the other on shrubs in the islands 
of Hyéres (near Toulon) and on rocksin the Channel Islands, and Ireland ; 
and three are natives of Chili. All the rest are inter-tropical; two of 
them reaching however within our southern limits. 
1 Massalongo (Ric. p. 149) had already made the same observation on the 
spores of this species, which he inclined then to refer to Arthonia. 
? These anomalies have been excluded, in the case of Opegrapha, by many 
writers (Enccphalographa, Massal. Lecidee sp., Nyl. Stictographa, Mudd) and 
this is one of the possible solutions of the question in which spore-series to place 
the genus. But the distinction of the divergent Opegraphe, by colour alone, is 
by no means so easy as that of Rinodina from Lecanora, or Buellia from Lecidea ; 
and the present writer has preferred, in view of similar but scarcely irreducible 
anomalies in Thelotrema, &e., to retain this natural genus in its entirety; and, in like 
manner, not to separate Chiodecton seriale and C.lacteum, Mont., from the group 
with which each has so much in common. The last-cited lichen of Montagne was 
but doubtfally referred by him to the C. lactewm of Fée; and it seems now impos- 
sible, in view of this author's description and figure of the spores of his species 
(Suppl. t. 40, Chiod. 4 bis) to consider the Cuban plant as associable with it. This 
may therefore appropriately take the name of its first describer (C. Afontagneai). 
