mm
54 SIPnONEiE.
scecl-vessel, whicli is of smaller size, rests almost immediately
on the incurved anther.
Found in fructification, according to Vaucher, in the
au tum n ; my specimens were obtained in a hedge at
Cheshunt in March, and were also in fructification.
b. Vesicles lateral, sessile, gemmate.
6. V aucheria aversa Hass.
Plate VI. Fig. 5.
Char. Capsules usually in pairs, and in the form o f a
bird’s head, xoith the beaks averted from each other. Sporangia
circular, not entirely filling the cavity o f the capsule.
Hassall, in Annals of Nat. Hist. vol. xi. p. 429.
llah. Vicinity of Cheshunt.
I have now met with this species repeatedly ; it is one of
the best marked and most peculiar of the genus, the
beaks of the capsules being turned in opposite directions at
once, distinguish it from aU other known species, in which,
when the vesicles are in pairs, they are directed towards
each other. This averted position of the capsules renders
the existence of a distinct horn or anther essential for each.
In the form of the seed-vessels, and in the circumstance of the
sporangia not filling the entire cavity, the species resembles
Vaucheria ornithocephala.
7. V aucheria ornithocephala Ag.
Plate VI. Fig. 4.
Char. “ Vesicles binate or quaternate, with a short beak, and
pellucid border, upon short, straight peduncles.”— Harv.
Grev. Alg. Brit. p. 193.; Hooker, Brit. Flor. p. 320.; Conf.
vesicata Dillw. Brit. Conf. t. 7 4 .; Harv. Manual Brit.
Algae, p. 148.
vaucheria. 55
Hah. Near Bristol: W. W. Young. A b o u tF d in h u rg h : Dr.
Greville.
This species would appear to be one of the rarest of the
genus. I have myself never encountered it.
8. V aucheria sessilis Vauch.
Plate IV . Fig. 2.
Char. Capsules pxjriform, large, sessile.
Ectosperma sessilis Vauch. Hist, des Conf. d’Fau douce,
Grev. Algae Brit. p. 192. ; Hook. Br. FI. p. 320. ; Fug.
Bot. t. 1765.; Ilarv. Manual, p. 148.
Tills is one of the most abundant species of the genus.
The vesicles arc almost as often solitary as in pairs ; and in
this state I apprehend it constitutes the Vaucheria dichotoma
of Avritcrs. The spores are frequently noticed to he of a
reddish colour. Tliis appearance is common to all the species
of the genus, and is probably the result of age, and also an
indication of the presence of azote.
c. Vesicles pedunculate, in pairs, lateral.
9. V aucheria geminata Vauch. •
Plate I I I . Fig. 1.
Char. Capsules situated on a divided peduncle, common to
both. Anther intermediate.
Ectosperma geminata Vauch. Hist, des Conf. p. 29. pi. ii.
fig. 5 .; Grev. AlgaiBrit. p. 193. t. 19 . ; Hook. Br. Fl.
p. 320. ; Fng. Bot. t. 1766.; Harv. Manual, p. 148.
The filaments of this species arc iiiucli finer than those of
any of the preceding ; the seed-vessels, too, arc smaller, and
represent a sphere holloAved out on the inner side, or towards
the anther. The peduncle is common to both seed-vessels:
after ascending for some distance from the filament from
which it rises, it sends off laterally two branches, on each of
E 4