Observations on British Zoophytes and Protozoa. 251 
and four other tubercles appear on the marginal canal, as 
shown in fig. 8 — a change analogous to that undergone in 
Bougainvillea Britannica. 
2. Atractylis coccinea^ n. sp. 
Polypidom creeping, widely reticulate. Polyp fusiform, set 
at an obtuse angle to its stalk, rich crimson or pink, with 
eight alternating tentacles, four long and four short. 
This zoophyte was found at Inchgarvie in August last, 
growing on the roots of Laminaria saccharina. The poly- 
pary consists of an open network of milk-white fibres, w^hich 
closely invests the branches of the root. From this net- 
work the polyp-stems are given oflP, each about a quarter of 
an inch in length, of a rich pinkish cream-colour, and bear- 
ing at its summit a single crimson polyp with a double row 
of transparent colourless tentacles. The body of the polyp 
is fusiform, sometimes nearly cylindrical, and consists of an 
endoderm having its cells laden with granules of the richest 
carmine-colour, covered by an ectoderm of transp arent 
white — a white blond dress over a crimson satin petticoat. 
The polyps, like others of this class, have the habit of turn- 
ing themselves inside out, when the internal surface of the 
deep-coloured velvety endoderm is readily observed. On 
such occasions masses of granular matter are frequently 
ejected, which are composed of small pigment-globules filled 
with crimson fluid. The tentacles are eight in number, 
four of which are long and held nearly erect, and alternate 
with the rest, which are shorter and more expanded. The 
thread-cells are inconspicuous. 
This beautiful little zoophyte, when seen with a single 
lens, presents a perfect garden of minute animal flowers 
covering the roots of the sea- weed. The reproductive appa- 
ratus was not observed. 
3. On Bhizopod Structure. 
One of the most interesting and important questions of 
the day to the comparative physiologist is that of the con- 
stitution of Ehizopod structure. The Foraminiferous or Bhi- 
zopod animals are before our microscopic eye every day. We 
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