Sphæroidea

“ The most simple group are the Stylosphærida, in which only one pair of spines is developed, indicating one single axis. These three families form together a continuous natural series,—the Sphæroidea with real dimensive axes,—and exhibit at the same time relations to the three other suborders of Sphærellaria, the Larcoidea, Discoidea, and Prunoidea respectively. ”

“ The section Discoidea comprises those Spumellaria in which the fenestrated shell is more or less discoidal or lenticular, flattened or compressed in the direction of one axis. The geometric fundamental form of the latticed shell, which in the Sphæroidea is a sphere, here becomes a flat disk, like a medal, or a biconvex lens, sometimes also a biconcave lens. The Discoidea can be derived from the Sphæroidea by shortening of one axis. This shortened vertical axis is the main axis of the disk; both its poles are constantly equal. ”

“ Also in the latest system of Ehrenberg (1875, loc. cit., p. 157) his Haliommatina are a confused conglomeration of different Spumellaria (Sphæroidea, Discoidea, and Prunoidea) .
The section Sphæroidea is the largest division of Sphærellaria, comprising not less than one hundred and seven genera and six hundred and fifty species. This enormous number (easily to be augmented by further investigations) requires a careful disposition in different families and subfamilies. For this disposition two different principles only can be employed: firstly, the number and disposition of the radial spines ”

“ Definition.—Androspyrida with a spherical or subspherical shell, without basal incision and transverse constriction; without free basal feet.
The genus Sphærospyris differs from all other Spyroidea in the regular spherical or spheroidal form of the lattice-shell. It may therefore be easily confounded with some species of the Sphæroidea; but the internal sagittal ring, placed in the median plane of the fenestrated sphere and connected with it by radial beams, leaves no doubt that it is derived from a true Spyroid, either Dictyospyris or Amphispyris, or another genus. ”

“ The simplest forms of Actissa (Procyttarium, Pl. 1, fig. 1) are in fact geometrically perfect spheres; indeed even the individual parts which compose their unicellular bodies (nucleolus, nucleus, central capsule and calymma) are concentric spheres. But in addition the central capsules of most other Spumellaria, especially the Sphæroidea, as well as of many Acantharia are true spheres. Furthermore the simple or concentrically composed lattice-spheres of Sphæroidea, Sphærophracta, and Phæosphæria may be regarded as spheres, although strictly speaking they are endospherical polyhedra. ”

“ Besides the tubules of the fenestrated shells, in some genera of Collosphærida the surface is armed with irregular thorns, rarely with more regular radial spines. But these spines obtain constantly the character of accessory by-spines, and remain short and thin. In this family typical radial spines never occur in a regular and characteristic disposition, corresponding to dimensive axes, as is the case in nearly all solitary Sphæroidea, only excepting the Liosphærida. Commonly these spines or thorns serve as protective arms for the shell-meshes, surrounding them often in the form of coronels. ”

“ The triangular meshes of the Sagosphærida are therefore on an average ten times as large as the usual meshes in the network of the common Sphæroidea.
The filiform bars, or the thread-shaped, very long and thin rods between the triangular meshes, are scarcely less characteristic of the Sagosphærida than the form and size of the meshes. Their length is usually between 0.1 and 0.2 mm., often also from 0.2 to 0.3 mm., whilst their thickness is only 0.002 to 0.004 mm., often it is less than 0.001, rarely more than 0.005 mm. ”

“ About three hundred species of very different groups (mainly Sphæroidea, Discoidea, Spyroidea, and Cyrtoidea) have been measured in this manner, and the general survey of the results obtained (about eight thousand measurements were recorded) has enabled me to form a good opinion of the constancy and variability of the dimensions in the individual species. The general result is, that they are not absolutely constant in any given case, but that each species (of which many specimens have been carefully compared) exhibits a certain degree of variability in all its proportions. ”

“ The Three Dimensive Axes—or the three diameters of the sphere, perpendicular one to another—are in the great majority of the Sphæroidea significant in the promorphological consideration of the body, and are indicated either by the position of the external radial spines, or at least of the internal radial beams, connecting the concentric spheres. Commonly two radial spines are placed opposite in each axis. The most perfect group in this respect seems to be that of the Cubosphærida, in which the three axes are represented by three pairs of spines. ”

“ Since such lentelliptical central capsules are developed even in Actissa (Actilarcus, p. 16) , it is possible that the simplest Larcoidea may have arisen directly from these by deposition of a simple lentelliptical lattice-shell in the sarcodictyum, on the surface of the calymma (Cenolarcus, Pl. 50, fig. 7) . It is more probable, however, that these simplest forms (Cenolarcus, Larcarium) have been developed from the simplest Sphæroidea (Cenosphæra) , by the spherical body growing unequally in the three dimensions of space. ”

“ At that time I could not separate them sufficiently from some Acantharia and Phæodaria, which have a similar spherical lattice-shell.
As the number of different genera and species in the Sphæroidea is much greater than in all other sections of Spumellaria, many forms were already described by former authors. In the oldest system of Ehrenberg (1847, loc. cit., p. 53) they represent one part of his Haliommatina (with four genera, Haliomma, Chilomma, Stylosphæra, Spongosphæra) . Most species, however, of these genera are Discoidea. ”

“ In general, their siliceous shells are firmer and more massive, usually also somewhat larger, but of simpler structure. The manifold delicate appendages (spines, bristles, feet, wings, &c.) which are so richly developed in the living Spumellaria and Nassellaria, and are also well shown in the Tertiary species, are entirely wanting in the majority of the Jurassic Polycystina. The Sphæroidea and Prunoidea are all simple spherical or ellipsoidal lattice-shells (Monosphærida) ; concentric lattice-shells (Polysphærida) are entirely wanting. ”

“ Their number and disposition is never regular nor symmetrical (as in the majority of Sphæroidea) and varies even in each single species. In general the number of main-spines varies between ten and forty (rarely less or more) usually between twenty and thirty. Their length is commonly about equal to the diameter of the shell, often somewhat shorter, rarely considerably longer. Their thickness is in the majority of species about equal to the diameter of one or two pores of the lattice. Sometimes they are much stronger, rarely thinner. ”

“ Sphæridea, 50.
Sphærocapsa, 798.
⁠cruciata, 798.
⁠dentata, 798.
⁠quadrata, 798.
⁠pavimentata, 798.
Sphærocapsida, 795.
Sphæroidea, 50.
Sphærophracta, 795.
Sphærospyris, 1099.
⁠globosa, 1100. ”

“ The oldest well-known form of Sphærozoida is the common cosmopolitan Sphærozoum punctatum, probably first observed in 1834 by Meyen, and called Sphærozoum fuscum, afterwards more accurately described by Huxley in 1851. ”

“ It is a curious fact that only adults and young, but none of intermediate size, happen to be known. This creature shows many important features. The vertebrae and ribs are not fused with, but remain free from, the carapace, and this is fundamentally different from and not homologous with that of other Chelonians. O. P. Hay has suggested that the mosaic polygonal components of the shell of Sphargis are, so to spea, an earlier generation of osteodermal plates than the fewer and larger plates of the Thecophora, which in them fuse with the neural arches and the ribs. ”

“ Internal parasites and "saprophytes," that is, beings which live on dead and decayed organic matter, on the other hand, live surrounded by a supply of dissolved food; and rarely do we find larger cells, richer in reserves, than in the parasitic Sporozoa, which owe their name to the importance of brood-formation in their life-history. In Radiolaria (p. 75 f.) a central capsule separates off an inner layer of protoplasm; the outer layer is the one in which digestion is performed, while the inner layer stores up reserves; and here brood-formation appears to be the rule. ”

“ Among the Phæodaria increase by cell-division seems to occur commonly in many groups, as in the Phæocystina, which have no skeleton (Phæodinida, Pl. 101, {cxxxvi}fig. 2) , or only an incomplete Beloid skeleton (Cannorrhaphida, Pl. 101, figs. 3, 6, and Aulacanthida, Pl. 104, figs. 1-3) . The Phæosphæria also (Aulosphærida, Cœlacanthida) and the Phæogromia (Tuscarorida, Challengerida) appear sometimes to divide; at all events, their central capsule often contains two nuclei. Of special interest is the spontaneous division of the Phæoconchia, especially the Concharida (Pl. 124, fig. 6) . ”

“ Genealogical Tree of the Spyroidea.—The extensive order Spyroidea is of especial interest in connection with the phylogeny of the Nassellaria, since all its members show two well-developed skeletal elements in combination, the sagittal ring of the Stephoidea and the latticed cephalis of the Cyrtoidea; the majority possess also the basal tripod of the Plectoidea (or a radial skeleton derived from it) . Hence there is a possibility of deriving the stem-forms of the Spyroidea from each of these three groups. ”

“ Spores with two polar-capsules, and without an iodinophilous vacuole in the sporoplasm. Mostly “free” parasites. Gen. Sphaerospora. Four or five species are known, from the kidneys or gall bladder of fishes (fig. 3, A) . One, S. elegans, is interesting in that it affords a transition between the two sections, being disporous. Gen. Myxidium; spores elongated and fusiform, with a polar capsule at each extremity. The best-known species is M. lieberkühnii, from the urinary bladder of the pike. One or two species occur in reptiles. ”

“ The Challenger collection has yielded a number of other true Thalassosphærida, which partly agree with Thalassosphæra in the simple structure of the unicellular body (resembling Actissa) , and partly differ from it in the development of alveoles, either within or without the central capsule (similar to Thalassolampe and Thalassicolla) . The solid siliceous spicula, which occur in great numbers scattered in the calymma, agree perfectly in form with the spicula of the colony-building Sphærozoida. ”

“ The assistant continued without hesitation, embarrassed by his incompetency, "A hyper-complex spheroid with radio interceptors, a-matter viewers and recorders and the general intelligence instruments of micro-size was placed in the cranium of the male mutant. The spheroid has negative direct control over the organism. ”

“ Therefore in the large central capsule of the mature solitary Thalassosphærida, we commonly find one large nucleus in the centre, and a number of oil-globules around it in the endosarc, or disposed in one layer on the inside of the capsule-membrane (Pl. 2, figs. 2, 5) ; whereas in the much smaller associated capsules of the Sphærozoida one large oil-globule is placed commonly in the centre, and a great number of small nuclei scattered in the endoplasm (compare above, p. 24) .
Synopsis of the Genera of Thalassosphærida. Genus 7. Thalassosphæra, [14] Haeckel, 1862, Monogr. d. ”

“ Genus 51. Amphisphæra, Haeckel, [50] 1881, Prodromus, p. 452.
Definition.—Stylosphærida with three concentric lattice-spheres and two free spines of equal size and similar form.
The genus Amphisphæra differs from its probable ancestral form, Stylosphæra, in the triple spherical lattice-shell. Commonly two of these lie within the central capsule (medullary shell) , whilst the third lies outside it (cortical shell) . But sometimes this order is inverted, the cortical shell being double, the medullary shell simple; and perhaps these forms may better represent a peculiar genus, Amphisphæridium. ”

“ Moreover, although the small attached worm in Sphærularia is not altogether exactly like the ordinary young ones, still, in size and general appearance, it remarkably resembles them; and, lastly, unless we may regard it as being the male, that sex is, as yet, entirely unknown. Although, therefore, I have not been able to distinguish any generative organs, or trace of spermatozoa, I think that I am justified in considering that in Sphærularia the male is far smaller than the female, and that the two are fastened together in a certain definite manner and position. ”

“ The dark brown sphaerulites are less perfectly round, and vary in diameter from the twentieth to the thirtieth of an inch; when broken they exhibit towards their centres, which are whitish, an obscure radiating structure; two of them when united sometimes have only one central point of radiation; there is occasionally a trace of or a hollow crevice in their centres. They stand either separately, or are united two or three or many together into irregular groups, or more commonly into layers, parallel to the stratification of the mass. ”