here and there to .a sphex'ical cell, which is sometimes
terminal.
1. SPHiEKOZYGA J aCOBI Ag.
Char. Threads radiating, lonelg, disposed in gelatine.
SphcBrozgga Jacobi Berk., in Eng. Bot. t. 2826. fig. 2.
Hah. Northamptonshire: Rev. 31. J. Berkeleg. Cromlyn
B o g : J. W. Gutch, Esq.
This species would appear from the description to belong
to Anabaina or Aphanizomenon. I have never seen it.
36. T R IC H O RM U S Allman.
Char. F rond/ree , o f undeterminate figure, consisting o f simple,
minute, moniliform, curved threads, with articulations o f
uniform size, immersed in a gelatinous matrix.
Derivation. From Spi^, hair, and opgos, a necklace.
“ From Anabaina of Bory Saint Vincent the present
Alga, as well as tha t of Mr. Thompson {Anabaina ? spiralis),
differs in the uniform size of the articulations, Bory’s genus
being characterised by larger globules occurring at distinct
intervals in the series.”— Allman.*
Although strongly inclined to agree with my excellent and
early friend Dr. Allman, as to the validity of the genus Tri-
chormus, I am still not altogether satisfied respecting it, the
suspicion resting on my mind tha t the T. incurvus Alim,
might possibly be an Anahaina in a young stage of its
developement, the reproductive enlarged cells not having as
yet manifested themselves. This, however, is but a suspicion,
against which may be urged the fact that in veritable Anahaina
the globules are invariably found interrupting the
uniformity of the filaments.
* “ On a New Genus of Algas, belonging to the family of the Nosto-
chinese.” By G. J. Allman, A.B., L.R.C.S.J., Secretary to the Dublin
Microscopical Society. Annals of Nat. Hist. vol. xi. p. 161.
1. T eichormus incurvus Alim.
Plate L X X V . Fig. 1. ?
Char. “ P lan t either diffused through the water or collected on
the surface. Filaments o f a pea-green colour, crowded
together confusedlg in a gelatijious matrix, variously curved,
hut never regularly spiral, assuming, when dried, a fine
verdigris-green colour without lustre.”—-Allman.
Allman in Annals of Nat. Hist. vol. xi. p. 163.
Hab. In the Grand Canal dock, Dublin, October: Dr.
Allman.
The only authentic specimen which I have seen of this
species was so much injured tha t I was not able to make an
examination of it in the least satisfactory. A specimen, however,
sent me by Mr. Thompson, collected by that gentleman
and found fioating on the surface of Lough Neagh, at Shane’s
Castle, marked Anabaina flos-aqua, accords so well with the
description and figure given by Dr. Allman of T. incm-vus,
th a t scarcely a doubt remains as to the propriety of regarding
Mr. Thompson’s plant as that species, see PI. L X X V . fig. 1.
From the true A. flos-aqua Mr. Thompson’s specimens differ
in the less considerable dimensions of the filaments, and in
the absence of the enlarged cells.
Section ii.
Filaments invested in a mucous matrix o f a definite form.
37. M O N ORM IA Berkeley.
Char. “ Frond branched, composed o f a single moniliform
thread, following the ramifications, immersed in gelatine.”
— Berk.
Derivation. From govos, one, and opgos, a necklace.
This genus scarcely differs from Nostoc, between which and
Anahaina it forms a clear link.
B ÏÜ