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a connecting link with another order, the Colmndliferae, where
the capillitium originates in a totally different manner. The
following arrangement illustrates the evolution of the genera
included in the Peritrieheae, and the points of affinity with other
orders—■
D ic t y d io m .
C k ib e a e ia .
Cl a t h r o p t y c h iu m . ®
Orccidella.
Q i>
M O
gP» og
a W
E n t e b i d i u m .— T u b u l i n a .— P r o to d e rm ium .
PEEITEICHEAE.
(B ritish g ene ra a re p rin te d in s m a l l c a p i t a l s , exotic g en e ra in italics.)
ANALYSIS OF THE GENERA.
PEEITEICHEAE.
Sub-sect. Tubulinak.
T u b u l in a . Sporangia crowded to form an aethalium.
Protodermium. Sporangia scattered.
Sub-sect. C b ib e a e ia e .
Oreadella. Sporangia perforated at the apex.
E n t e b id iu m . Sporangia with small lateral perforations, or
broken up into an irregular network.
C l a t h r o p t y c h iu m . Sporangia with large symmetrical openings
in side walls, apices of sporangia permanent.
Ceibeaeia. Permanent portions of upper p a rt, or whole
of sporangium forming an irregular network.
D ic t y d iu m . Permanent ribs of sporangium radiating from
the calyculus and converging towards the apex, joined by
thinner transverse bars.
Sub-sect. Tubulinae.
T ubulina, Pers. (emended).
Sporangia scattered and regular, or irregular and forming a
plasmodiocarp, or compacted together to form a naked or corticated
aethalium ; walls very thin, single, often iridescent, not
perforated; columella and capillitium absent.
Tubulina, Persoon, Syn. Fung., p. 197 ; Rost., Mon., p. 219
Cooke. Myx. Brit., p. 54; Sacc,, SylL, Vol. vii. p. 406 ; Schroeter
p. 102; Zopf, p. 172 f. licea, Schrader, Nov. PI. gen,, p. 17 ; Rost.
Mon., p. 218; Schroeter, p. 102 ; Zopf, p. 171; Sacc., Syll., Vol
vii. p. 404; Cooke, Brit. Myx., p. 54. Lindbladia, Fries, Summ
Veg. Scand., p. 449; Rost., Mon., p. 223 ; Cooke, Myx. Brit, p
55; Saco., Syll, Vol. vii. p. 408; Zopf, 172.
A careful examination of ample material has convinced me
that the three genera given above constitute but one natural
genus, and Tubulina, having priority, has been adopted. The'
structure and origin of an aethalium being unknown to the old
mycologists, explains the origin of these genera; but it is
remarkable that Rostafinski, who so lucidly explains the origin
and value of aethalia, did not notice the sequence so clearly
stated in his own diagnoses of the three genera, which he
retains. In all three the sporangial walls agree in being
membranaceous and not perforated; lAeea has the sporangia
regular, as in L. minima, Fr., or irregular and forming a
plasmodiocarp, as in L. flexuosa, Pers.; in T%Cbulina the sporangia
are cylindrical or prismatic from mutual pressure, and combined
to form a naked aethalium; while in Lindbladia, the sporangia
also form a naked aethalium, but although prismatic, as in
Tubulina, are not quite so much elongated; finally, the species
described as Licea spumarioides, Cke. and Mass., belongs to one
of the trio, but differs from all in having the sporangia flexuous,
and in the aethalium being covered with a common cortex. If
Rostafinski’s view as to the autonomy of the three genera in
question is correct, it follows that the aethalioid condition of
such species as Hemiarcyria rubiformis, Rost., must not only
be separated fi-om the form with simple, normal sporangia,