. Text-book of zoology for junior students. Zoology. 34 INVEKTEBIfATE ANIMALS. closely to the Foraminifera ; ami the resemblance between the two groups is still further increased by the fact that the jjseudopodia often run into one another so as to form a network, and sometimes show a eiiculation of granules along their edges. Theie is generally a central capsule surrounded by a layer of saicotle ', and the latter usually contains coloured cells. A contractile vesicle is usually wanting. _Foui- princijial groujjs of organisms have been described as belonging to the li'-iiUuhtria, and
. Text-book of zoology for junior students. Zoology. 34 INVEKTEBIfATE ANIMALS. closely to the Foraminifera ; ami the resemblance between the two groups is still further increased by the fact that the jjseudopodia often run into one another so as to form a network, and sometimes show a eiiculation of granules along their edges. Theie is generally a central capsule surrounded by a layer of saicotle ', and the latter usually contains coloured cells. A contractile vesicle is usually wanting. _Foui- princijial groujjs of organisms have been described as belonging to the li'-iiUuhtria, and we may briefly notice an example of each of these. In the first family we have organisms like Acanthometm (fig. 13, a), in which the body is composed of sarcode, supported by a fiamework of siliceous or flinty rods, which all meet in a common centre. The sjiines or rods are all perforated by canals, and each con- veys a pseudo])odium, which is jirotruded from an aperture at its. Fi;^. l:t.—a Acnnthometra knicolata ; b HaUmnmn h^racaiUJnim, "111- .if the I'ulyaj^Umi (after Mlillev). apex. Many pseudopodia, however, are given off from the surface of the body directly, and are not enclosed in the spines. The Acan- thometnE are all minute, and are found floating near the surface in the ojjen ocean, sometimes in great ntimbers. In the second family (Poli/ri/stiiix, fig. 13, h) we have a ntnnber of lieautiful little organtsms allied to the Font mi u (fern, but ditl'ering in tlie fact that the body is enclosed in a glassy shell composed of flint. The shell is ].>erforated by numerous holes through which the i>seudo- prjilia are emitted, and it is usually of extreme beauty, being sculp- tured in various ways, and often adoined with spines. The sarcode of the body is usually olive brown in colour, and often does not quite fill the shell. Tlie |)seudop)odia are filamentous, and exhibit a slow circulation of granules al(jng their borders, but they do not run into one another
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1885
