JA
merata ((7. Brownii) arise from the sub-immersed habitat in
which it grows. Mr. Harvey thus describes C. Brownii : —
“ This forms exceedingly dense, very rigid tufts, of a black
green colour when growing, but on having the water
expressed, and being held to the light, exhibits a beautiful
yellow-green tint. Filaments so matted together, tha t it is
difficult to separate a single thread. They appear to originate
in a mass of creeping, branched, densely matted fibres,
which form the base of the tufts. They are erect, from half-
an inch to an inch high, fiexuous, very rigid and elastic ; the
branches few and nearly simple, almost always secund, very
erect. A very curious and distinct plant, having, to the
naked eye, a good deal the appearance of Vaucheria terrestris,
but totally different in structure. I t is perhaps allied to C.
oegagropila, I have examined a specimen from Mr. Brown in
the late Mr. Templeton’s herbarium, and find it to agree in
every respect Avith my Wicklow plant.”
2. C la do pho ra c r is pata .
Plate LV . Pigs. 1, 2.
Char. Filaments very tenacious and o f variable diameter,
crisped, and entangled.
C. nigricans Dillw. Conf. Syn. 1. c. ; Harv. 1. c. p. 356.
C. crispata Sm. E. Bot. t. 2350 ; Harv. 1. c. p. 356.
C. flavescens Harv. 1. c. p. 356. ; E. Bot. t. 2088. ;
W y a tt, Alg. Darm. No. 224. C. frac ta Dillw. Conf.
t. 14. ; E. Bot. t. 2338. ; Harv. 1. c. p. 356. Microspora
Hass, in Annals, vol. xi.
Hab. Everywhere common. Var. nigricans in a pond at
Wimbledon, Surrey ; Mr. Dickson.
Three British species of Confervoe appear all referrihle to
this one : these are C. nigricans, C. fracta, and C. flavescens.
C. flavescens I take to he the young state of C. crispata,
while C. frac ta is assuredly the mature or perfect condition
of the plant ; it is also equally certain that the C. nigricans
of Dickson is merely a discoloured state of C. crispata.
JL
The suspicion also may, I think, be entertained, th a t C.
crispata itself is but a condition of C. glomerata, changed by
the difference of its place of growth — it growing for the
most part in still Avater, in deep ponds, and lakes. I have
often seen‘specimens, which it would be impossible to refer
with certainty to either species. A specimen of C. capillaris
in the Linnsean Herbarium, was referrihle to this species, or
condition of one.
19. C O L E O C H Æ T E Dre/.
Char. “ Frond disciform, appressed, parasitic, formed o f filaments
radiating from a centre, generally conjoined. F ilaments
articulated, dichotomously branched, sending fo rth
in all directions from the upper surface o f the cells cylindrical,
truncated, lengthened, setigerous sheaths. Endochrome
green.” — Breb.
Derivation. From koXsos, vagina, and seta.
1. C o l eo c hæ t e scutata Breb.
Plate L X X V I I . Fig. 6.
Char. Filaments appressed, conjoined, radiating, so as to
describe a disciform frond.
fl soluta. — Filaments radiating, prostrate, free.
Coleochæte scutata Brèb. Description de deux nouveaux
Genres d’Algues fiûviatiles, Ann. des Scien. Nat., J a n vier,
1844, p. 25. pi. 2.
Hab. In stagnant waters and ditches, growing on submersed
leaves and stems of aquatic plants. Autumn —
spring. Near Manchester : Mr. Sidehotham. Aberdeen
: Dr. Dickie. Near Clonmel : Prof. G. J. Allman.
“ I have found this remarkable Alga in many places in
the environs of the town of Falaise. I t grows closely applied
upon the leaves and stems of inundated and in part decomposed
plants. I have gathered it principally upon Sparga-
nium natans, and upon the Potamogetón natans. Its lenticular