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, which 

 closely invests the branches of the root. From this net- 

 work the polyp-stems are given off, 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 Ehizopod 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 Ehi- 

 zopod animals are before our microscopic eye every day. We 



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