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Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index: Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII — John Shaqi

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Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index: Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

Name: Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index: Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII
Author: Haeckel, Ernst

Haeckel, Ernst

Radiolaria

_The Central Capsule_ of the Plagonida exhibits the general characters of
all MONOPYLEA (compare above, p. 890). It is commonly ovate or ellipsoidal,
with vertical main axis; on the lower pole of the latter is the porochora
(or the "area porosa," from which all pseudopodia radiate). This is in
immediate connection with the central point or central rod of the skeleton,
in which its radial spines are united. The topographical relation of the
supporting skeleton to the central capsule seems to exhibit in the
different genera of the Plagonida remarkable differences, as already
demonstrated above (p. 905).

{908}_Synopsis of the Genera of Plagonida._

  -------------------------------------------------------------------------
  I. Subfamily Triplagida. Three radial spines.
  -------------------------------------------------------------------------
  Three spines lying in one horizontal plane,          384. _Triplagia_.

  Three spines corresponding to the edges of a flat
    pyramid,                                           385. _Plagiacantha_.
  -------------------------------------------------------------------------
  II. Subfamily Tetraplagida. Four radial spines.
  -------------------------------------------------------------------------
                              {All four spines equal,  386. _Tetraplagia_.
  Four spines arising from    {
    one common central point. {One apical spine
                              {  opposed to three
                              {  basal spines,         387. _Plagoniscus_.

                              {All four spines equal,  388. _Plagonidium_.
  Four spines arising in two  {
    pairs from the poles of a {One apical spine
    common central rod.       {  opposed to three
                              {  basal spines,         389. _Plagiocarpa_.
  -----------------------------------------------------------------
  III. Subfamily Hexaplagida. Six radial spines.
  -----------------------------------------------------------------
  Six spines arising from one common central point,    390. _Hexaplagia_.

  Six spines arising in two opposite groups from the
    poles of a common central rod,                     391. _Plagonium_.
  -----------------------------------------------------------------
  IV. Subfamily Polyplagida. Numerous radial spines.
  -----------------------------------------------------------------
  Numerous (seven to nine or more) radial spines
    arising from a common centre (either a central
    point or a branched rod),                          392. _Polyplagia_.



Subfamily 1. TRIPLAGIDA, Haeckel, 1881, Prodromus, p. 423.

_Definition._--#Plagonida# with three radial spines.



Genus 384. _Triplagia_,[3] Haeckel, 1881, Prodromus, p. 423.

_Definition._--#Plagonida# with three radial spines, arising from one
common central point and lying in one horizontal plane.

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Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index: Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

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