(176) 
responding to our section Rhizocarpon in Buellia. Of this convenient 
but artificial section we possess two species. ——H. leucoranthum (Spreng.) 
(Lecidea, Spreng. in Act. Holm., 1820, p. 46. Nyvl.in Prodr. Fl. N. Gran. 
p. 69. Heterothecium tricolor, Mont. Syll. p. 341. H. bicolor, Flot. in Bot. 
Zeit. 1.¢.). Swamps in the upper country of North Carolina (Rev. Dr. 
Curtis) South Carolina (Mr. Ravenel) Alabama (Af. Peters) Mississippi 
(Dr. Veitch) Louisiana (Hale) Texas (Mr. Ravenel). Otherwise only 
intertropical. Spores solitary, large, oblong, more or less yellowish- 
brownish, the at first grumous protoplasm developing into many small 
spore-cells, crowded together in (15-25) somewhat regular (but soon 
irregular) annular series, like coarse mason-work; from three to four 
times longer than wide.——H. pezizoideum (Ach.) Flot. in Bot. Zeit. 1. c. 
(Lecidea, Ach. Nyl. Scand. p. 212. Lopadium, Koerb. Syst. p. 210. Th. 
Fr. Lich. Arct.-p. 201. Biatora vernalis 3, f., Fr. L. E. p.264. Trachylia 
pheomelana, Tuck. Lich. exs. n. 98).—On fir bark in the White Moun- 
tains; and in Maine (Myself) and on cedars, New Bedford (Mr. Willey). 
On the earth, growing over mosses, Greenland (J. Vahl, e Th. Fr. 1. ¢.) 
and in islands of Behring’s Straits (Mr. Wright). A northern lichen 
which the turbinate (substipitate) apothecia well distinguish from all but 
the Cuban H. turbinatum (Lecidea, Tuck. Obs. Lich. 1. ¢.). Another 
northern species of the present section is H. fusco-luteum (Dicks.) of 
alpine districts in Scotland (Herb. Dicks. Herb. Hook.) first referred to 
its true affinity by Mudd (Man. Brit. Lich. p. 190) which may well occur, 
at least in arctic America. 
It has been remarked above that the obvious affinity of two or three 
myriosporous lichens of the present family is with Heterothecium ; and 
that there is nothing to associate them with Biatora § Biatorella but the 
abnormal character of their spore-evolution; an irregularity by no means 
confined to Biatora. One of these lichens was referred here by Flotow; 
and another resembles this. The third, though associable only with a 
very different cluster, is yet equally at home here-——H. conspersum 
(Fée) Flot. in Bot. Zeit. 1. ¢. (Wright Lich. Cub. n. 224). A tropical 
species, which has occurred in southern Alabama (Mr. Beaumont). 
Spores exceedingly minute, and numerous; globular.——H. nannarium, 
Tuckerm.,' a dwarf indeed in this large-fruited genus — the apothecia 
scarcely reaching 0,3™™- in width—is otherwise generally comparable 
with the last; but the disk of the fruit is not powdery (conspersus) and 
the thekes, instead of being long-club-shaped, are ovoid. I have it only 
from Texas (Mr. Wright)——H.. Wrightii, Tuckerm. (Lich. Cub. n. 235) 
a Cuban myriosporous species, with the aspect of a state of H. tubercu- 
losum, may possibly prove to occur within our southern limits. 
1 Heterothecium nannarium (sp. nova) thallo granuloso-farinoso citrino ; apo- 
theciis valde minutis (0,15-0,25™™- lat.) sessilibus sub-planis, disco ferrugineo-fusco, 
margine flavicante. Spore in thecis ovoideis numerosissime, minutissime, globu- 
lares, incolores, paraphysibus parcis.—On bark, near the Blanco, Texas (C. Wright). 
The reaction with iodine is blue. 
