to Mudd, unknown. Nor am I satisfied that, amo 
DR. LINDSAY ON NEW-ZEALAND LICHENS. 497 
Systematists have laid much stress on the presence or absence of cyphellæ, or pseudo- 
eyphelle, as a means of distinguishing Sticta, Stictina, and Ricasolia. Their presence 
and absence, however, are most capricious; and even in the true genus Sticta, as defined 
by Nylander, species are to be found which are acyphellate, cyphellate, or pseudo- 
eyphellate. There is considerable variation in regard to the smoothness or roughness of 
the surface of the thallus, and the nature and extent of division of the margins of its 
lobes. The same species which has at one time a smooth thallus, exhibits it in other eir- 
cumstances subfossulate, or roughened by granulations, or furfuraceous with a minute 
squamulose growth, as to the upper surface. The under surface may be in the same 
species smoothish, or granulose, or fibrillose, to various extents. The edge of the divi- 
sions of the thallus is sometimes still further and very minutely subdivided into a mass of 
squamusculæ, which may assume the form of columnar isidiiform growths of subcoralloid 
aspect. Sometimes, apparently especially in sterile conditions of the thallus, it is 
covered with dense masses of these squamuscles or granulations. Some species are never 
found save in a sterile state; and in these cases it is at least doubtful, I think, whether 
they are all autonomous species. In many species the thallus is extremely liable to 
decortieation or erosion of the cortical layer, whereby the differently coloured medullary 
tissue is prominently exposed. Sometimes this erosion is general, involving the whole 
thallus; more generally it affeets it only in irregular patches. 
It appears to me, on the one hand, that there is no sufficient ground for the generic 
separation of Stictina and Ricasolia from Sticta *, and, on the other, that the number of 
book species of all these three genera admits of material reduction. 1 allow that 
the Sticte are naturally divisible into three groups—the central, highest, or typical one 
represented in this country by Sticta pulmonacea and S. damecornis, and in New vid 
land by S. fossulata and S. latifrons. Of the other two, one connects Sticta with = “ 
gera, and is represented by such species as Stictina fuliginosa ; the other Mae - : 
With Parmelia, the representatives whereof are Ricasolia herbacea or R. glomu 2 ^ 
do not, however, think that these groups possess characters admitting of their distinc 
limitation ; the general resemblances are much more weighty than any m iid 
stant differences. In regard to book species, I have found, by watching aic po : is 
in the same locality, transition forms connecting two species 50 intima : unde I 
impossible for me to believe them distinct. Thus, in the Pass of on p sud 
ve found Stictina sylvatica and fuliginosa passing freely = t i What is 
teptibly that I am forced to regard both as referable to one specific type. 
; : ‚its apothecia being, according 
called sylvatica seems to be the sterile form of the ae pee Pip ele 
‘Manual,’ or, among New-Zealand sport 
S. Urvillei, S. granulata, S. dissimulata, 
tagnei of Nylander's Lich. N.Z.t are 
Jans, S. intricata, and S. ciliata of Mudd's 
that Stictina dissimilis, Sticta subcoriacea, 
: fossulata, S. physciospora, and Ricasolia Mon 
autonomous. 
* Memoir on Spermogones, pp. 191 & 201. » Journ. of Linnean Society, Botany, 
t Lichenes Novæ Zealandiæ quos ibi legit anno 
* x. p. 244, 
1861 Dr. Lauder Lindsay, 
