44 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Spores with 2 or more cells. 
Spores 2-celled, thallus commonly gran- 
ular or verrucose.........-....-.--- BIATORINA (p. 82). 
and our one species of MELASPILEA (p. 59). 
Spores more than 2-celled. 
Spores 4 to 9-celled, fusiform or finger- 
shaped; thallus granular or verru- 
COS@........--------------.-.---- Binimsta (p. 84). 
and our one species of LEcANACTIS (p. 60).¢ 
Spores 4 to 16-celled, very slender (acic- 
ular); thallus granulose, chinky, 
subareolate or subsquamulose.... Bacrpra (p. 85). 
Spores commonly brown. 
Spores 2-celled, or rarely 4-celled; thallus 
granulose, verrucose, or areolate...... BUELLIA (p. 92). 
Spores at first 4-celled, passing into muri- 
form, rarely hyaline; thallus verrucose, 
areolate, or rarely subsquamulose. - . - - RHIZOCARPON (p. 97). 
and our last species of SECOLIGA (p. 62). 
Apothecia commonly more or less elongated or 
irregular. 
Apothecia elongated and sometimes 
branched. 
Apothecia superficial or partly immersed, 
oblong to linear, rarely rounded, sel- 
dom branched................-.....-. OPEGRAPHA (pp. 52), 
Apothecia more or less immersed, linear or 
rarely short, usually curved and fre- 
quently more or less branched... .... GRAPHIS (p. 04). 
Apothecia commonly more or less irregular. 
Spores medium-sized, hyaline or brownish, 
with 4 or rarely more cells........... ARTHONIA (p. 55). 
Spores large, muriform, hyaline or brown- 
Ish... eee eee ee ARTHOTHELIUM (p). 58). 
DESCRIPTIONS OF FAMILIES, GENERA, AND SPECIES.» 
Family CALICIACEAE. 
The character which most readily distinguishes the Caliciaceae is the gelatinization 
and dissolution of the upper portion of the asei before the spores are mature. The 
a See also the first species of Secoliga (p. 62). 
6 The following trees are cited as substrata of lichen species: 
Balsam. The balsam fir, Abies balsamea Mill. 
Birch. The canoe or paper birch, Betula papyrifera Marsh. 
Cedar. The white cedar or arbor-vite, Thuja occidentalis 1. 
Elm, The American white elm, Ulmus americana 1.. and perhaps the slippery or 
red elm, Ulmus fulva Michx. 
Oak. Quercus macrocarpa Michx., Q.alba L., Q. rubra L., Q. velutina Lam., Q. coccinea 
Moench. 
Pine. The white pine, Pinus strobus L., the red or pitch pine, P. resinosa Ait., and 
the gray or jack pine, P. divaricata Du Mont de Cours. 
Poplar. Populus balsamifera L., P. deltoides Marsh,, P. grandidentata Michx., 2. trencu- 
loides Michx. 
Spruce. The black spruce, Picea mariana (Mill.) B. 8. P., and the white spruce, 
P. canadensis (Mill.) B. 8. P. 
Tamarack. The larch, Larix americana Michx. 
