← Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) / Report on the Scientific Results of the Voyage of H.M.S. Challen

Order I. Collodaria, Haeckel, 1881

Collodaria, Haeckel, Prodromus, 1881, p. 469.

Collida et Sphærozoida, Haeckel, 1862, Monogr. d. Radiol., pp. 246, 522.

Definition.—Spumellaria without latticed shell.

The order Collodaria, the first order of Radiolaria, comprises all those Spumellaria in which the skeleton is either entirely wanting, or represented by numerous single, solid, siliceous needles or spicules, loosely scattered in the calymma around the central capsule. Never in this order is there any trace of the latticed or fenestrated shell, which characterises the second order, Sphærellaria. The skeleton exhibits no trace of phylogenetic connection in the two orders.

In my monograph (1862) two families appertaining to this order are described, the Collida (p. ) and the Sphærozoida (p. ). Both families contain forms with and without a skeleton. Of the solitary or monozous Collida the Thalassicollida are devoid of a skeleton, whilst the Thalassosphærida are provided with a skeleton. Of the social or polyzous Sphærozoida the Collozoida are without a skeleton, the Rhaphidozoida provided with one. As the special form in both skeletophorous subfamilies is exactly the same, I prefer now to associate them in the suborder Beloidea, and to oppose them to the other two skeletonless subfamilies, which are united under the name of Colloidea.

Synopsis of the four Families of Collodaria.

Suborder I. COLLOIDEA.

Skeleton entirely wanting.

Solitary cells, living as isolated individuals (Colloidea monozoa), 1. Thalassicollida.

Associated cells, living in colonies or cœnobia (Colloidea polyzoa), 2. Collozoida.

Suborder II. BELOIDEA.

Skeleton composed of numerous needles or spicula, scattered in the calymma.

Solitary cells, living as isolated individuals (Beloidea monozoa), 3. Thalassosphærida.

Associated cells, living in colonies or cœnobia (Beloidea polyzoa), 4. Sphærozoida.

Skeleton entirely wanting.

Solitary cells, living as isolated individuals (Colloidea monozoa),

1. Thalassicollida.

Associated cells, living in colonies or cœnobia (Colloidea polyzoa),

2. Collozoida.

Suborder II. BELOIDEA. Skeleton composed of numerous needles or spicula, scattered in the calymma.

Solitary cells, living as isolated individuals (Beloidea monozoa),

3. Thalassosphærida.

Associated cells, living in colonies or cœnobia (Beloidea polyzoa),

4. Sphærozoida.