74 
PACIFIC SCIENCE, Vol. II, April, 1948 
described, but does not believe that it is suffi¬ 
ciently distinct to be worthy of recognition. 
Phaeopeltosphaeria irregularis Wehmeyer, 
sp. nov. (Fig. 1) 
In superficie caulis maculas dense dispersas, 
ellipticas, 1-1.5 mm. longas, 0.5 mm. crassas, 
tumidas, nigricantes formans; ostiolo centrali pa- 
pilliformi vix erumpenti; perithecia 300-550/a 
diametro, 200-350/a alta, singula in lignum sub 
maculis clypeiformibus immersa; pariete crasso, 
prosenchymatoso, ab ligno adjacenti separate; 
asci late cylindrici, 90-95 /a longi, 12.5/a crassi, 
saepe 6-7-spori; paraphyses numerosae, fili- 
formes, persistentes, 1 /a diametro; sporae uni- 
seriatae, subglobosae vel ellipsoidales, 10.5-18/a 
longae, 7-9/* crassae, olivaceae, varie septatae, 
1-cellulae vel muriformes, cum .1-3 septis trans- 
versalibus, ad septa constrictae, cellulis ali- 
quibus verticaliter 1-septatis. 
Appearing on the surface as thickly scattered, 
elliptic, raised, blackened spots, 1-1. 5X0.5 mm., 
with a central, barely erumpent, papillate 
ostiole; perithecia 300-550 X200-350/*, im¬ 
mersed singly in the wood, beneath a clypeus- 
like blackening of the surface tissues; wall 
10-20/a thick, prosenchymatous, free from the 
surrounding wood tissue which is somewhat 
blackened; asci stout-cylindric, 90-95 X 12.5/a, 
with a claw-like base, and often with only 6 to 
7 spores; paraphyses numerous, persistent, fili¬ 
form, 1/a in diameter; spores uniseriate, subglo- 
bose to ellipsoid, 10.5-18 X 7-9/*, olive-brown, 
variously septate, one-celled to muriform with 
one to three transverse septa and one or more 
Fig. 1. Phaeopeltosphaeria irregularis: a, radial 
section of a perithecium showing the clypeate blacken¬ 
ing of the surface; h, ascospores, illustrating variation 
in septation; c, ascus with ascospores. 
cells with vertical septa, somewhat constricted 
at the septa. 
Galapagos: South Seymour Island. On 
dead, decorticated wood of Bursera graveolens, 
September 6, 1945, 6251, type. 
The genus Phaeopeltosphaeria Berk and Pegl. 
(1892:139) was based upon P. caudata, on 
woody stems, which might be considered as a 
Peltosphaeria with brown spores or a Pleospora 
with a clypeate blackening about the peri¬ 
thecium. It has fusoid spores which are much 
larger than those of P. irregularis . Phaeopelto¬ 
sphaeria panamensis Stev. and King. (Stevens, 
1927:50) seems to be the only subsequently 
described species. Its spores are described 
merely as "muriform, fusiform; olivaceous or 
straw-colored; 16x5/*,” but the figures (81-83) 
given show them to be more irregularly 3- 
septate than in this species and with tapered 
rather than rounded ends. It is also found on 
leaves of Chaetochloa, and the authors state that 
it resembles the spots of Phyllachora Chaeto- 
chloae Stev. on this host. On the basis of this 
latter statement, Petrak (1929:387) claims that 
P. panamensis is a Pleospora [Pleospora pana¬ 
mensis (S. & K.) Petr.] and probably parasitic 
in the Phyllachora stroma. 
The collection from the Galapagos Islands is 
quite distinct from either of these described 
species. It is true that there is a variable degree 
of blackening of the tissues above the peri¬ 
thecia of certain species of Pleospora, but if the 
genus Phaeopeltosphaeria is to be recognized at 
all, this collection is a typical species. 
BASIDIOMYCETES 
Sebacina petiolata Rogers 
On dead wood of Bursera, 6246. Recently 
described (Rogers, 1947:99) from Cuba, 
Hawaii, and the Marshall Islands. The Gala¬ 
pagos collection, determined by D. P. Rogers, 
was growing at the base of an old dead trunk of 
Bursera beneath the soil level and was revealed 
only when the trunk was pulled over. On the 
