(179) 
and in Ogden, Utah (Dr. Lapham) but there exists also a specimen in 
Schweinitz’s herbarium which may possibly have been collected in the 
United States. The ‘bad lands’ of Nebraska, where Placodiwm fulgens, 
and Buellia epigea were found by Professor Hayden, may possibly yet 
increase our knowledge of the present group. , 
To the far less conspicuous assemblage of forms represented by 
L. enteroleuca, Ach., we have to add L. vitellinaria, Nyl., a parasite of 
the thallus of Placodium vitellinum, which has been found in Greenland 
specimens of the Placodiuwm by Dr. Th. Fries (Lich. Arct. p. 222) and 
has occurred to me in Rocky Mountain ones (Prof. Hayden). Rock- 
forms of LZ. enteroleuca are not uncommon throughout the country, from 
Nebraska (Dr. Hayden) to Pennsylvania (determ. Nyl., Dr. Michener) and 
North Carolina (Rev. Dr. Curtis) and sometimes (Vermont, Mr. Frost) 
sufficiently resemble specimens of his L. sabuletorum f. arenaria (L. sabu- 
letorum, Koerb., Th. Fr.) determined by Flotow. But the minutely 
granulate thallus of the last is at length more distinctly areolate-verrucose, 
and such acondition (v. theioplaca, areolis verruculosis in crustam pallide 
stramineam congestis) occurring on serpentine rocks in California (Mr. 
Bolander) might easily be taken for distinct, yet agrees with the present 
species in its spores, and spermatia, and only differs in colour (though 
this is interesting in its bearings on the true rank of the cited ZL. sabzele- 
torum) conformably to the variations of the bark-lichen. From some of 
these saxicoline states appears scarcely to differ otherwise than in habitat 
the v. muscorum (L. sabuletorum, v. muscorum, Th. Fr. Biat. Wulfenii, 
Hepp) occurring in Greenland (J. Vahl, e¢ Th. Fr. J. c.) and in islands of 
Behring’s Straits (Mr. Wright).——Other muscicoline and terricoline 
Lecidee accompany the last in arctic and alpine districts, of which 
L. arctica, Sommerf., is not uncommon in the alpine region of the White 
Mountains; and has been found also in Greenland (Th. Fr. /. c.) and, with 
the last, by Mr. Wright.——L. pallida, Th. Fr., readily distinguished 
from L. arctica by its pale thallus, has also occurred im Greenland (J. Vahl, 
1. c.). ——And L. borealis, Koerb., was collected by Mr. Wright in islands 
of Behring’s Straits, the specimens agreeing with Scher. Helv. n. 195, as 
also with authentic ones of ZL. alpestris, Th. Fr.1—— L. turgidula, Fr. 
1 The latter name is given, as in many similar cases by recent writers, in what 
I must consider mistaken deference to the L. sabuletorum 8, syncomista, b, alpestris 
of Sommerfelt. But the author of the Supplement to the Flora Lapponica did 
not refer his lichen to any ‘‘ Lecidea alpestris,” but to L. sabuletorum, —that is to 
an old species; and the writer who first proposed for it the rank of a new one, 
should seem to have a right to the credit of it. And I shall venture here to 
express anew the opinion, —for correction at least, if it require it, —‘that the 
name which may happen to be given to a variety has,no precedence ; but may be 
adopted or not, if the plant be taken up as a species.’ The case is the same with 
sections of genera. The other method has at least the objection that it makes the 
earlier writer whose variety-name it is sought to elevate into a species-name 
