(146 ) 
horizontal thallus of P. acicularis agrees generally with that of P. fibula, 
in which this feature was first observed. In other respects these two 
plants differ, externally, scarcely otherwise than in size; and the spores, 
in any large view, not appreciably. All which is equally true of the rela- 
tions of the robuster, arctic condition (P. robustus) to the original type 
(P. acicularis.)! 
XXXIN.—CLADONIA, Hoffm. 
Hoffm. Pl. Lich. 2, p.2; D. Fl p, 114. Scher. Spicil. pp. 18, 278; Enum. 
p.183. Floerk. de Clad. Comment. p.5. Fr. L.E.p.205. Eschw. Lich. 
Brasil. 1. c. p. 260. Tuckerm. Syn. N. Eng. p. 47. Mass. Mem. p.75. 
Koerb. Syst. p. 15. Nyl. Syn. 1, p. 187, t. 6, £. 24-30; Lich. Scand. p. 49. 
Th. Fr. Lich. Arct. p. 145; Lich. Spitzberg. p. 28. Stizenb. Beitr. 1. c. 
p. 167. Cenomyce, Ach. L. U. p.105; Syn. p. 248. Cladonia, Seypho- 
phorus, and Pycnothelia, Fée Ess. p. 83. Patellarie sect., Wallr. 
Naturgesch. d. Siulchen-Flecht. p.5; Fl. Crypt. Germ. 1, p. 395. Het- 
erodea, Cladonia, & Cladina, Nyl. Syn. Lich. N. Caled. p. 9. 
Structuram expos. Tulasne, Mém. sur les Lich. pp. 24, 36, 171, t. 10, 
_ f.6-11,t.11, f.11-7; Schwendener, Untersuch. 1.c.2, p. 168, t.6, f. 23-27. 
Apothecia patelleformia excipulo proprio, mox cephaloidea, sub- 
inania. Sporze ovoideo-oblonge, simplices, incolores. Spermatia 
bacillaria; sterigmatibus simpliusculis. Thallus horizontalis squam- 
uloso-foliaceus aut crustaceus, verticalem fistulosum subsimplicem 
aut fruticuloso-ramosum subinde granuloso-squamulosum (podetia) 
proferens. 
1 In conformity with this view, the arrangement of the forms of Pilophorus, 
known to me, will be somewhat as follows:—P. acicularis (Ach.) (Cenomyce, 
Ach.) — West coast of Nurth America, Menzies, &c.—f. fibula (Stcreveuulon, 
Tuck. Pilophorus, Th. Fr.)— Moist rocks in the mountains of Eastern America, 
Tuckerman, &e.—f. robustus (Piloph. Th. Fr. P. polycarpum, Tuckerm.)— 
Moist rocks in Norway (Blytt) and Finmark (Th. Fr.) as in islands of Behring’s 
Straits (C. Wright). Spores of the Western lichen, as seen in specimens from fire 
collectors, from ellipsoid becoming more or less fusiform, and measuring from 
0,012. to 0,024™™- in length, by 0,005™™- to 0,008™™- in thickness. Those of 
f. fibula, as seen in my own specimens, are less fusiform than the spores finally 
become in the Western lichen, and measure 0,018™™- to 0,023™™- in length, and 
0,005™™- to U,007™™. in thickness; in the New York specimens they vary however 
from ellipsoid to clubshaped and fusiform, measuring from 0,014™™- to 0,027™™- 
long, and from 0,005™™- to 0,008™™- thick. And those of f. robustus, in my Fin- 
mark specimens (Herb. Th. Fr., & Lich. Scand. rar. u. 11) are also rather ellipsoid, 
measuring from 0,160™™- to 0,023™™. in length, and from 0,005™™- to 0,008™™- in 
thickness; but become longer and fusiform in the plant from Behring’s Straits, 
measuring now 0,023™™- to 0,025™™- in length, and 0,005™™- to 0,007™™- in 
thickness. 
