circular, extending into a portion o f the connecting tubes.
T. stagnalis.
Hassall, in Annals of Nat. Hist. vol. x. p. 42.
Hab. Abundant on Hertford Heatb and other places in
the counties of Hertfordshire and Essex: A. II. II.
Rusthall Common; Waterdown Forest, and near Cross
in Hand.
This is a distinct and common species. Fig. 10. plate
XXXVIII. may possibly be distinct from this.
Second subgenus. — Sporangia lodged in the transverse tubes.
7. T y n d a r id ea immersa Hass.
Plate X X X IX . Fig. 3.
Char. Filaments o f considerable diameter. Cells about once
and a h a lf or twice as long as hroad. Endochrome distinctly
stellate. Sporangia large, circular, and partly immersed
in the cells.
Tyndaridea conspicua. Annals of Nat- Hist. vol. xii.
p. 187. pi. 7. fig. 17.
Hab. Wimbledon Common : A. II. II.
“ This species bears considerable resemblance to Vaucher’s
figure of T. pectinata. I do not think, however, tha t it is
tha t species, for I presume tha t Vaucher employed the same
magnifying power to all his figures; in which case the filaments
of T. pectinata would be almost equal in diameter
to those of Z. quininum, and consequently nearly as large again
as those of the present species.”— Annals.
8. T y n d a r id ea co nsp icua Hass.
Plate X X X IX . Figs. 1, 2.
Char. Filaments rather smaller than those o f the preceding
species. Cells usually twice, or tivice and a h a lf as long as
hroad. ^ Sporangia usually spherical, but sometimes oval,
and entirely confined to the transverse tubes.
lyndaridea immersa. Annals of Nat. Hist. vol. xii n 188
pi. 7. fig. 19.
Hab. Wimbledon Common: A. II. II.
A very rare species. I have seen it but once.
9. T y n d a r id ea decussata Hass.
Plate X X X IX . Fiftfo. 6.
Char. Filaments o f less diameter than those o f the precediny
species. Cells usually two and a h a lf times as long as
broad. Sporangia circular, and a portion o f them immersed
either in one or other, or both cells.
T. decussata Hassall, in Annals and Mag. of Nat. Hist,
vol. xii. p. 188. pi. 7. fig. 18.
The species described by Vaucher, under the head of Conjugata
decussata, would appear to he referrihle to the next
genus, and not to Tyndaridea.
10. T y n d a r id ea R a l e s i i Hass.
Plate X X X IX . Figs. 4, 5.
Char. Filaments o f less size than those o f T. immersa. Cells
usually fo u r times as long as broad. Sporangia elliptical,
their long diameter corresponding with the length o f the
tube.
Hab. Penzance: Mr. Ralfs. Near Cross in Hand, opposite
to where the road branches to Hailsham, and on
Piltdown Common.
T. Ralfsii Hassall, in Annals of Nat. Hist. vol. xii. p 188
pi. 7. fig. 20. ^ ‘ .
“ There is not a more beautiful or elegant species than
this in the genus, and I have much satisfaction in dedicating
It to Mr. Ralfs, its first finder, and a gentleman by whom
M 3