P l a t e LVIII. A.
CALOTHRIX LASCICULATA, Ag.
G e n . C h a e . MlamenU destitute of a mucous layer, erect, tufted, or aggregated,
fixed a t th e base, somewhat rigid, n o t oscillating. Tube continuous
; endochrome green, densely annulated, a t length dissolving
into lenticular sporidia. C a l o t h e i x (Aî-.)— from K a U s , beautiful,
and dp'ii, a la ir . ________________________
CALOTHEix/asCTcafcfe; stratum velvetty, dark green, of indefinite ex ten t;
filaments very straight, subulate, much attenuated, fascioulatety pseudo-
branohed.
C a l o t h r ix f a s c i c u l a ta , Ag. Syst. p. 71 {excl. syn.). Ilarv. in H o ff. Br. M.
vol. i i p. 368. Harv. in Mack. M. Hib. part 3. p. 237. Harv. Man. p. i5 o .
H a b . Spreading over th e surface of marine rocks, about half-tide level ;
probably common. Annual? F ound a t all seasons. Miltown Malbay,
W.H.H.
G e o g e . D i s t e , Baltic Sea. British Islands.
D e s c e . Stratum of indefinite extent, from a few inches to several feet m diameter,
of a dark, shining green colour. Filaments from two to three lines m height,
tufted erect, straight, tapering to a long, setaceous, peUucid pomt. In an
early stao-e of growth they are quite simple, and sometimes remain so, but
m o f e generally they are furnished with from two to six or more, erect,
closely pressed pseudo-branches. Striæ or annuli strongly marked, and closely
set. Colour under the microscope, a deep, glaucous green.
This is nearly related to C. scopulorum, which I have therefore
figured on the same plate ; and I am by no means sure tbat it
should not be considered as merely a more developed form of
that plant, tbe differences being occasioned by its growing at a
greater deptb, and in places where it is more constantly submerged.
The filaments are taller, straighter, more acuminate,
and of a deeper green than in 0. scopulorum, and very frequently
are furnished witb tufts of accessory brancbes, but tins is a
character of minor importance.
The genus Calothrix, as defined by Agardh, contains many
species, the majority of which, as of the Oscillatoriece in general,
are found in fresh water. By Kiitzing this genus has been
broken up into several, and formed into a distinct family, an
innovation of very questionable character, productive of a host of
new synonymes.
A V ri 1. C a l o t h e ix f a s c ic u l a t a . Portion of the stratum-.—¿/ie
size. 2. A tuft of filaments. 3. Apex ot a f i l a m e n tmagmjied.