two appear to be identical, that tf. veiled only was fertile, with spofeS 
double the size of U. polyrrhisa or 18-22 by to-12 /d. If these Specimens 
from Archarius were identified before he reached definite conclusions regard- 
ing the specific limits of If. veiled , comment is Unnecessary. But if they 
were determined on characters set forth in Li. tjm. p. 673 1 . C. there may be 
several inferences. Either Nylander is in error and if. vetted should hdvi 
large spores : or large spores are concomitant to both tf sPddockrod and tf. 
veiled : or, the other physical characters of one or both plants may be incon- 
stant, or finally the arbitrary separation of the two on sporal or other 
differences may be without justification. The delimitation of two lichens 
identical in other respects, because of difference in size of the spores is 
abhorrent to a conception of natural species. The thallus of an ash-colored 
Umbilicaria sp. on which are ultimately developed the apotheeia of tf. 
veiled and tf. spddochrod is none the less specifically one or the other 
despite its infertility, and if the thought is carried further until the larger 
spores of tf. spadochroa have assumed their full size, may it not be proper 
to call the species U. veiled ? 
An endeavor to learn something of V . veiled from the writings of 
Linnaeus is frustrated by the terseness of his descriptions. In “ Species 
Plantarum,” 3d Edition, p. 1617, Lichen velleus is described as “ Lichen 
foliaceus umbilicatus subtus hirsutissimus ” and quoting himself in “FI. 
Lapp.” the author amplifies with “ Lichen folio subrotundo feltato margin 
fere integro, subtus inaxime hirsutus.” Linnaeus cites the illustration in 
“ Historia Muscorum of Dillenius,” Fig. 5, pi. 82, as representative of the 
form, and the Rev. J. M. Crombie proves to us that the Linnaean guess or 
Dillenian drawing were both good. In his “Lichens of Dillenius Historia 
Muscorum, illustrated by his herbarium.” Crombie says “ that the specimen 
of U. veiled in Herb. Dill, to which is attached the descriptive label of 
‘ Lichenoides coriaceum latissimo folio umbilicato et verrucoso’ is sterile, 
and “the specimen of which the figure is not at all good, represents a very 
large and old state of the species.’ ” 
One wonders how Crombie recognized a “ sterile” .state of if. veiled with 
the certainty indicated by his words, but that must remain a mystery so far 
as present knowledge helps. It may be pointed out as a curious considera- 
tion at this juncture that while type specimens of U. veiled (L. ) Nyl. have 
been preserved, no one can state with definiteness whether they are repre- 
sentative of veiled or spddochrod as those plants are now understood. 
Acharius in Li. Um p. 673 1 . c. was first to make the effort of clearly mark- 
ing limits for each of the two species. It is conceivable from Nylander’s 
words (Syn. 1 . c. ) that the Archarian dissociation impressed him as being 
fundamental. Th. Fries, “ Lichenographia Scandinavica,” considers that 
while Acharius rightly knew U. veiled , his recognition of spddochrod might 
be questioned. Whatever view is taken of the Acharian conclusion, the 
uselessness of going behind his amended diagnosis had been made apparent. 
As the early writers delimited species almost entirely on macroscopic 
characters, it will be a matter of interest to learn if possible in what respect, 
