442 BOTANICAL GAZETTE [JUNE 
beneath; branches dichotomous. A pothecia lateral, subcyathiform, 
exciple rugose, disk chestnut-brown. Spores 11-16X7-9 BF. 
SUBSTRATA: On the ground. 
GEOGRAPHICAL DISTRIBUTION: Mexico. 
OxpsERVATIONS: This rare North American plant has been only recorded 
from Mexico. It seems in every way logical that this species should there- 
fore stand last of the Evernias, and next before the Parmeliaceae in our tax- 
onomy. This relation has been assigned this genus by ZAHLBRUCKNER, with 
the removal of Cetraria into the Parmeliaceae, where it occupies a position 
preceding Evernia. et 
Hue records Evernia intensa Nyl.5 from Mexico. The specs 
is apparently a chemical one, of which there is probably but little 
material. I have been unable to see the plant. 
In closing this paper it is a great satisfaction to learn that at 
the Congress at Brussels Linnaeus Species Plantarum (1753) has 
been approved as the starting point for lichenological nomenclature. 
The labor involved here and in my Usnea paper in settling the 
priority of names is therefore not in vain. 
For the opportunity to complete this paper I am indebted 
largely to Dr. N. L. Brirron, who extended me during the past 
year a Garden Research scholarship, which was unfortunately 
cut short by ill health. To many others connected with the New 
York Botanic Gardens, to Dr. G. C. ALLEN, Dr. L. W. RIDDLE, 
Dr. Frep. Exrvinc, Prof. Bruce Fink, Dr. H. E. Hasse, DR- R. 
W. Drecuster, Mr. L. K. Lunt, and numerous other friends Iam 
also most grateful. 
THOREAU MusEuM 
Concorpb, Mass. 
EXPLANATION OF PLATES XXIV AND XXV 
Fic. 1.—Drtrentus plate of Evernia prunastri (L.) Ach. (Lichenoides) : 
Fic. 2.—Drtentus plate of Evernia divaricata (L.) Ach. (Lichenoides) : 
Fic. 3.—Retz1us type of Lichen arenarius=Evernia divarica 
Fic. 4.—DILtentus plate of Evernia furfuracea (L.) Mann. ( 
Fic. 5.—Evernia Trulla (Ach.) Mont. from a specimen in the U.S. 
Herb. 
Fic. 6.—Acharian types of Evernia furfuracea and varieties Lee 
Fic. 7.—Evernia furfuracea var. ceratea (Ach.) Nyl. collected 9 9 
by L. K. Lunt. 
i 
Lichenoides)- 
U.S. Nat. 
's Flora 30:546. 1872; and Bull. Soc. Linn. Norm. 6:269. 1872- 
