** Species red or brownish.
P leurococcus m in ia tu s. (.KuU) Nag. Mnz. A lg .p .d 6 .
Cells very variable in size, globose, usually single, rarely 2-4
in a family, seated on a broadly effused red stratum, which is
more or less gelatinous. Cell-membrane rather thick, colourless,
hyaline, contents oleaginous orange.
S iz e . Cells-0037--016 mm. f ÆaJA.), -0035--015 mm. (Kirch.).
Eabh. Alg. iii. p. 27. Ea'bh. Exs. 31, 368, 1777. Kirch.
Alg. Schl. p. 115.
On the walls of conservatories, all the year.
This is one of the species in which Braun has observed the “ skinning
off ’’ of the outer cell-membrane.
Nageli ascribes the red colour occurring in many Palmellaceoe, partly
as anormal, partly as an abnormal phenomenon, to the formation of an
orange-coloured oil in the place of the chlorophyll.* Braun says that
probably all these have the power of retaining their life a long time in
the dried condition ; in the above species at least, he is quite sure of it.
The brownish-red colour often acquired by Protococcus viridAs may probably
be explained in the same way.f
Plate I I . fig. 5. Cells magnified 400 diam.
P leurococcus ro seo -p e r sic in u s. Rabh. Alg. iii., 28.
Aquatic. Cells unequal, cloudy, single or binate, tegument
hyaline, collected on a thin, rather gelatinous peaoh-rose coloured
stratum.
S iz e . Cells -0015--004 mm.
Protococcus roseo-persicinus, Kutz, Tab. i. t. i.
Clathrocystis roseo-persicinus, Cohn, Beitr. iii. ('18751. t 6
f. 1-10.
Investing submerged aquatic plants.
This very minute species, with cells of a peach colour, is not un.
common about the débris of decaying plants in pools. The cells are
usually agglomerated in spherical or elliptical masses. Certainly not a
good Pleurococcus,
Plate I I . Jig. 6. Cells magnified 400 diam.
Genus 3. 6I.ÆOCYSTIS. Nag. (1849.)
Cells globose or oblong, either single or 2-4-8, associated in
globose families. Common and special integuments gelatinous,
lamellose. Division in alternate directions. Propagation by
zoogonidia.
The lamellose tegument distinguishes the species of this genus from
Pleurococcus. Its analogue in the Phycochromaceæ is Glæocapsa.
* More or less green.
Glæ o cy stis am pla. Kutz.
Thallus gelatinous, rounded, lobed, dirty green. Cells globose,
or rounded oblong, 2-4-6 (rarely 8), associated in families
; tegument colourless, gelatinous, distinctly concentrically
stratose. Contents green, granular.
* Einzelliger Algæ, p. 9. f “ Eejuvenesoenoe,” p. 213, note.
S i z e . Cells -009--012 mm., fam. ■Ü43--09 mm. (Rabh.).
Eabh. Alg. iii. p. 29. Kirch. Alg. Schl. p. 112, partly.
Gleocapsa ampia, Kutz. Sp. p. 216. Tab. 3, f. 3.
Pleurococcus superbus, Cienk. Bot. Zeit., 20 Jan., 1865, p.
21. Archer Micr. Journ., 1866, p. 63.
Fixed to submerged plants.
Braun states that he has observed an irregular bursting and peeling
oH of the outer coat of multioellular families or sometimes of isolated
cells surrounded by manifold coats in this species, and G. vesiculosa.*
Plate 111. fig. 1. Cells magnified 400 diam.
G læ o cy stis v e s icu lo s a . Nag. Mnz. Alg. p. 66, t. 4.
Thallus gelatinous, green; cells small, globose, as many as
64, and more, associated in families ; tegument hyaline, colourless,
lamellose, lamellæ often breaking up ; contents green,
delicately granular.
S i z e . Cells 0045--0075 mm.. ; fam. -036 mm. (Rabh.).
Rabh. Alg. iii., 29. Rabh. Exs., No. 707.
Glæocystis ampla var. vesiculosa, Kirch. Alg. Schl. p. 112.
On wood and stones in stagnant water.
In character this species resembles the last, but the cells are smaller.
See also Ciëntowski’s paper in “ Botanisohe Zeitung ” for 20 January,
1865, where this species is figured to the same scale as Olæocystts
ampia.
Plate I I I . Jig. 2. Cells magnified 400 diam.
G læ o cy stis x u p e stiis. (Lyngh.) Rahh. Alg. iii., 30.
Thallus more or less expanded, dirty green, gelatinous, rather
firm; cells globose, middle-size, associated in families -, teg u ment
colourless, pellucid, distinctly lamellose, soon diffluent ;
contents green, granular ; sporangia globose, containing from
4-12 gonidia.
S i z e . Cells -0037--005 mm. ; fam. -06 mm. ; sporang. -085
mm. (Babh.).
Rabh. Krypt. El. Sachs, p. 128. Rabh. Exs. 1790. Kirch.
Alg. Schl. p. 112.
Palmella rupestris, Lyngb. Hyd. 207, t. 69. Hook. Eng.
El. v. p. 397.
On rocks, moist walls, and damp earth.
“ I t occurs as a dirty yellowish gelatinous crust often hanging down
in flakes from the face of the rock.”—Carm.
This is not, or only in part, the Ilæmatoeoccus rupestris, Hassall (p.
326, t. 82, fig. 1), which is chiefly applicable to Glæocapsa polyderma-
tica, K.
Plate T i l l . Jig. 1. Cells magnified 400 diam. a, from wet rooks ;
b, from damp earth.
* See Braun, “ Eejuvenesoenoe,” Bay Society, p. 182.