11. TY N D AR ID EA Bory.
Char. Endochrome disposed in the cells in a star-like form,
the stellate masses being double in each cell. Sporangia
usually circidar, sometimes lodged in the cells, and occasionally
in the connecting tubes.
Derivation. Tyndaridce, the constellation so called of Castor
and P o llu x ; in allusion to the twin star-like masses
contained iu each joint.
Stellidina Link, Handb. iii. 261. Agardhia Gray. Glo-
bulina Link, in Hor. Physic. 5. Lucernaria Rouss.
et Desv., Jour. Bot. i. 143. Tyndaridece et Ledce. species
Bory, in Diet. Class. Conjugatce, sect. 11. Vauch. pi. 6, 7.
The species of the genus Tyndaridea are distinguished by
the arrangement of the endochrome, which is in star-like
masses, two of which are contained in each cell, connected usually
hy a band or tube. Concerning the nature of these bodies,
numerous conjectures have been hazarded. It has been supposed
that the one represented the male and the other the
female, the sporangia resulting from their union: this conjecture,
however, does not seem probable. This form, as well
as the beautifully spiral arrangement of the endochrome, in
the genus Zygnema, has doubtless been impressed upon these
plants by the Deity, in order that they might appear the
more attractive and more wonderful in the eyes of man.
The sporangia are usually circular, and lodged either in
the cells themselves, or in the transverse tubes. By this difference
in the situation of the sporangia, the genus admits of
a natural division into two subgenera.
First Subgenus. — Sporangia placed in the cells o f one or other
filament.
1. T y n d a r id ea cruciata Hass.
Plate X X X V I I I . Fig. 1.
Char. Filaments o f considerable size. Cells once or once and
a h a lf as long as broad, at f r s t densely fil e d with endochrome,
ivhich near the period o f conjugation exhibits a
somewhat stellate arrangement. Sporangia circular, not
producing any material change in the primary form o f
the cell.
Conjugata cruciata Vaucher, Hist, des Conf. pi. vi. fig. 4.;
pi. vii. fig. 2. p. 77.
Hab. Cheshunt: A. H. H.
I have but little doubt that this is the Conjugata cruciata of
Vaucher. It is the finest of all the Tyndaridece I have met
with. It is not common: and I have only once obtained it
Avith the sporangia formed.
2. T y n d a r id ea anomala Ralfs.
Plate X X X V I I I . Pigs. 2, 3.
Char. Filaments smaller than those o f T. cruciata. Cells in
the young state usually about as long as broad, densely
fi l e d with endochrome, and invested with a broad and
very apparent mucous sheath; in a more advanced condition
the threads become narrower, the sheath smaller,
and the endochrome more scattered, and sometimes even
stellated; fn a lly , the sporangia are formed, which arc
circular, and protrude slightly into the tubes o f communication
o fth e flaments.
T. anomala Ralfs, MSS.
Hah. Penzance and DolgeUy : Mr. Ralfs. High Beech :
A. H. H. In a boggy spot near Cross in Hand, opposite
to where the road branches to Hailsham; Barcombe,
in Sussex, and Weston Bogs, near Southampton: Mr.
Jenner.
This remarkable and someAvhat anomalous species was first
discovered by Mr. Ralfs, who submitted it to the examination
of several friends. F or a long time, however, doubts were
entertained by many as to Avhether it really was a Tyndaridea
or n o t; doubts which I myself, in common Avith others,
for a period entertained, but which I was happily enabled to
M