82 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Collected at Rose Lake along the northern boundary. On old wood. 
Referred to by Tuckerman, but without giving localities. Known also in Europe 
and Asia. 
Heterothecium sanguinarium affine of the preliminary reports. 
BIATORINA Mass. Ric. Lich. 134. /. 262-271. 1852. 
The thallus is crustose and commonly granulose and often passes into verrucose 
or rugose-verrucose conditions, but is seldom or never in any degree areolate. It is 
thinner as a whole than that of Lecideas and is more commonly rudimentary or eva- 
nescent. The thallus development is on the whole better than in Biatorella, but 
there is no suggestion of a cellular cortex in any of the species examined. Neither 
are there any internal tissue layers. Asin the closely related genera, the rudimentary 
structure lies mainly above the substratum and is attached by hyphal rhizoids. 
The algal cells, in oursat least, are the common Cystococcus, though others insist that 
Chroolepus is the common form. 
The apothecia are usually small or minute and are commonly adnate. The 
exciple is as in section Biatora of the Lecideas, and frequently disappears, leaving 
the apothecium without margin. The disk is flat or more or less convex. The 
hypothecium and the hymenium vary in color from pale to brownish or brown, 
though bluish or pale violet shades are to be looked for in the upper portion of some 
hymenia. The spores are 2-celled, hyaline, and variously ovoid, oblong, ellipsoid, 
or even somewhat fusiform. 
The genus is doubtless derived phylogenetically from some form or forms of 
Lecidea, and this view is strengthened by the fact that among the Lecideas, and prob- 
ably among Biatorinas also, there are species having both simple and 2-celled spores. 
On the other hand, the relationship between the present genus and Bilimbia is per- 
haps as close, and it appears reasonable to suppose that the Bilimbias were derived 
from certain Biatorinas, by a second cell division of the spores, or the latter perhaps 
more probably from the former by spore degeneration, the same being true for Leci- 
deas and Biatorinas. The exciple is a rather weaker structure even than that of the 
section Biatora, and this condition and the presence of a septum in the spores removes 
the members of the present genus further from our common Eulecideas than from 
members of the above section. In some respects the species of the genus Gyalecta 
as viewed by Tuckerman seem quite closely related to the present genus, or to 
Bilimbia or Bacidia. It may well be questioned, in view of the transitional forms, 
whether Lecideas and Biatorinas should be separated. 
Thus far only five representatives of Biatorina have been met with in Minnesota. 
Four occur on wood and the fifth is parasitic on another lichen. 
Type species Biatorina griffithti (Ach.) Mass. loc. cit. 
KEY TO THE SPECIES. 
Parasitic on Peltigera, with very inconspicuous thallus and 
apothecia..... 220... 0. 02.0 ee ee ee eee eee 3. B. heerii. 
Not parasitic on other lichens. 
Thallus remaining ashy. 
Spores normal; thallus inconspicuous and apothecia 
small or minute..........---.....22---2000 eee eee 1. B. tricolor. 
Spores sometimes simple; plants otherwise asabove...la. B. tricolor atlan- 
tica. 
Thallus not often finally ashy. 
Thallus usually becoming greenish or brownish; apo- 
thecia small or minute, brown or blackish........... 2. B. atropurpurea. 
Thallus olivaceous-greenish or blackish; apothecia 
small or minute, brown or becoming blackish. .....- 4. B. prasina. 
