(275 ) 
(Verrucaria, Tuck. in litt. Trypethelium porosum, Mont. in litt. T. pyren- 
wloides, Mont.,eNyl.). Trunks, South Carolina (Mr. Ravenel). Alabama 
(Mr. Beaumont). Louisiana (Hale). Texas (Mr. Ravenel). In regard 
to this, the finest of our Pyrenule, I find myself compelled to differ from 
authorities, either of which I should be glad to follow. My late valued 
friend, Dr. Montagne, referred the Carolina lichen, with an ‘wt videtur, 
to Trypethelium porosum, Ach.; and this when his own 7. pyrenuloides, 
with which Dr. Nylander associates our plant, was already described. I 
have no specimen of T. porosum, distinguished, according to Nylander, 
‘perithecio incolore vel tenuissime infuscato,—an observation in which 
however he differs from his cited authorities —but the North American 
lichen is scarcely a Trypethelitm. This is equally the view of the author 
last cited; yet his own reference of the plant to that section of his 
Verrucaria (Prodr. Fl. N. Gran. p. 115) which constitutes Pyrenastrum, 
is perhaps quite as difficult to accept. The specific name is, at any rate, 
no longer available; and Iadopt that under which I long since distributed 
Carolina specimens. Spores of the North American specimens of P. 
pachycheila before me readily distinguished from those of Pyrenastrum 
astroideum by amore oblong outline; the number of cells in the trans- 
verse series of spore-cells scarcely exceeding two, while in the Pyrenastrum 
these are commonly from three to five. Perfect spores with eight to ten 
entire spore-cells occur also; and the passage from these, which are 
undistinguishable in type from those of Pyrenula of Koerber, into the 
multilocular modification (Polyblastia pr. p., Mass. Sporodictyon pr. p., 
Stizenb.) is easily seen.——P. lactea (Mass.) (Blastodesmia dein Poly- 
blastia, Mass., Koerb. Pyrenula Naegelii, Hepp). Trunks, White Moun- 
tains, on Rock Maple. New Bedford, Mass., on Ash, &c., (Mr. Willey). 
North Carolina (Rev. Dr. Curtis). South Carolina (Mr. Ravenel). Spores 
muriform, fuscescent or colourless, contained, very commonly in fours or 
sixes, in oblong, ‘subpedicellate’ thekes, and measuring 0,027-46™™. in 
length, and 0,012-18"™"- in width. But they also occur in eights, and 
smaller; measuring now 0,014-23™™ in length, and 0,003-10™™- in width ; 
corresponding sufficiently thus with the spores of Polyblastia sericea, 
Mass. (Lich. Ital. n. 262) which is scarcely distinguishable except by the 
differences in dimensions. A lichen from Texas (Mr. Wright) scarcely 
formes dein aggregatis nigris. Spore octone, ex ellipsoideo oblonga, submuri- 
formi-multiloculares (ser. transv. 8-10, long. 2-3) fuscescentes, longit. 0,030-69™™., 
crassit. 0,014-23"™-, paraphysibus capillaribus. Verrucaria pyrenuloides, Nyl., 
fide ipsius.——Trunks at the extreme south ; the range of the lichen being similar 
to that of Pyrenastrum astroideum, which often accompanies it, and may even be 
confounded with it. With iodine, the hymenial gelatine of P. pachycheila reddens, 
for the most part; but not always. Small forms of the species occur; and one of 
these (P. thelomorpha, Mihi in litt.) with apothecia only 0™™-,4-0™™.,7 in diameter, 
and spores not exceeding 0,023-30™™- in length, and 0,007-11™™- in width, deserves 
a separate place. 
