I. COLLODARIA. { Skeleton entirely wanting, 1. #Colloidea.# Skeleton wanting or { quite imperfect, { Skeleton represented by not latticed. { numerous scattered spicules, 2. #Beloidea.# II. SPHÆRELLARIA. { Lattice-shell spherical or { composed of concentric spheres, 3. #Sphæroidea.# Skeleton a perfect { shell of lattice { Lattice-shell ellipsoidal or work, or spongy and { prolonged in one axis, 4. #Prunoidea.# resembling { wicker-work. { Lattice-shell discoidal or { shortened in one axis, 5. #Discoidea.# { { Lattice-shell lentelliptical, { with different extent of growth { in three axes, 6. #Larcoidea.# ---- 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. 244) and the Sphærozoida (p. 521). 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#. {10}_Synopsis of the four Families of Collodaria._ Suborder I. { Solitary cells, living COLLOIDEA. { as isolated individuals { (_Colloidea monozoa_), 1. THALASSICOLLIDA. Skeleton entirely { wanting. { Associated cells, living { in colonies or coenobia { (_Colloidea polyzoa_), 2. COLLOZOIDA.