it is an Alga. It is indeed a true Scytonema, which bears
much resemblance to Petalonema alatum, though it wants
the characteristic feature of that very curious production.
Radulum aterrimum of Fries, of which specimens
are published in Scleromycetes S u e d and to which Per-
soon’s var. cornutum is referred, is altogether different, and
truly a fungus.—M. J . B.
2826 (Fig. 2.)-.
SPHiEROZYGA Jacobi.
Jacobi’s Sphcerozyga.
CR YP TO GAM I A Alga.
Gen. Char. Stratum mucous, containing jointed
simple threads; articulations here and there he-
teromorphous.
Spec, Char. Threads loosely disposed, radiating ;
heteromorphous joints globose and elongated.
Syn. Sphaerozyga Jacobi. Ag.inDiar. Ratisb. 1827.
Ic. Alg. Eur. no. 35.
Nostoc anisococcum. Spreng. Syst. Veg. v. 4. 372.
Schwabe in Linmea, v. 11. 12(5. t. 2. ƒ. 14.
O N mud in swampy ground, by the side of a brook at
King’s Cliffe, Northamptonshire, July 2, 1838.
Consisting of a thin dark green, more or less mucous
stratum, mostly amorphous, but sometimes very
obscurely lobed, from which the threads radiate, as in Os-
cillatoria limosa, in every direction, though to a much less
extent. Threads much curved, or straight, consisting of
subquadrate-submoniliform articulations, here and there
interrupted or terminated by others which are globose or
elongated. Frequently four elongated articulations, with
a globose one in the centre, are interposed. The substance
which connects the articulations is so transparent that I
have not been able to detect its outline under a magnifying
power of 600 diameters. In this state it has also been
figured and described by M. Schwabe.
This very curious genus is allied on the one hand to