(154) 
d. Cryptogamenk.; in Bot. Zeit. 1850, p. 382. Biatora max. p., et Se- 
colige sp., Norm. Con. pp. 18-22. Psora, Biatora max. p., Pyrrhospora, 
Psilolechia, Biatorina max. p., Bilimbia, Tricholechia, Bacidia, Ropal- 
ospora, Sporacestra, Scoliciosporum, Biatorella, et Chiliospora, Mass. 
opp. varr. & Auctt. pl. 
Structuram exposuerunt Tulasne, Mém. sur les Lich. p. 151, 167, 
t. 10, f 28-381; Fuisting 1. c. p. 30. 
Apothecia patelleformia, excipulo proprio ceraceo colorato dein 
sepius cephaloidea. Spore ex ellipsoideo simplici oblonge bi-quad- 
riloculares 1. fusiformes 1. aciculares dein pluriloculares, incolores. 
Spermatia (quantum observ.) ex oblongo bacillaria; sterigmatibus 
subsimplicibus. Thallus crustaceus, effiguratus aut uniformis. 
The genus is accepted here, generally, in the sense of Fries ; certain 
species, as those referable to Beomyces, and Heterothecium, being how- 
ever excluded. It is exactly analogous to Lecanora, and, like this, 
exhibits, but in greater fullness and detail, the whole differentiation of 
the colourless spore. All the steps of this process are displayed also in 
the central group of most closely allied forms (modifications in fact of but 
a single natural species according to Fries) of which B. vernalis, B. sphe- 
roides and B. rubella are well-known northern representatives. It is 
impossible to sunder, generically, these species, and the groups which 
they represent, by any differences beyond those based on, and represent- 
ing the successive steps in the process of development of what is, at the 
bottom, the same spore. And the more or less arbitrary assemblages of 
species which we thus gain, if available now as subordinate divisions, are 
perhaps as often undesirable breaks in the continuity of the larger natural 
group, or genus. 
For the naturalness of this group, and the distinctness of the series of 
forms which constitutes it from that exhibited by Lecidea will scarcely be 
denied; however difficult the extrication of its real rank in the system. 
The number of assumed species of Biatora and Lecidea, as here 
understood, taken together, is now as large as its reckoning is difficult. 
Not a few of these forms are, with little doubt, integrant parts of species 
the true limits of which are still undetermined. Even the groups best 
studied, as those of the northern hemisphere, and especially of Europe, 
are still, many of them, far from settled; and there is no question that 
many new forms are yet to be ascertained, some of which may well throw 
important light on the old. Most of the European Biatore are common 
to North America; which possesses some others unknown elsewhere, or 
at least to Europe. The genus has long occupied the attention of our 
lichenists; but the want of authentic foreign specimens has hindered 
some of these, otherwise best qualified, from satisfactory judgments: 
which only the long-continued, kind assistance of friends and correspond- 
