Type species:Spongosaturninus ellipticus  Campbell and Clark (OD)
Description:Spongostylinae with 3 concentric shells, outer shell spongy, inner a double lattice shell, and having 2 equal polar spines, distal ends of which are connected by an elliptical ring.
Remarks:Possibly this new genus was derived from Saturninus by the development of a spongy, instead of latticed cortical shell, from Saturnalis by the addition of a spongy shell to the 2 concentric shells, or from our other new genus, Spongosaturnalis, by the addition of inner shells to the spongy shell.
Stratigraphic range:Upper Cretaceous, Mesozoic.
Etymology:[No information given]
Subsequent descriptions:YES
Synonymized with ACANTHOCIRCUS by Pessagno, 1977b.

Description and dimensions:Shell very large, with elliptical ring which has at either narrow end a very long spine; cortical shell subelliptical (its greatest extent about 0.2 transverse axis of ring and spines), composed of a wickerwork of delicate loose polygonal frames of various sizes and dissimilar forms, from outer surface of which arises an even looser tangle (or outer zone) of more delicate, freely anastomosed, branched radial spines, this outer zone of cortical shell forming a beautiful, delicate, arachnoidal feltwork, inner zone of cortical shell less delicate but also spongy; outer medullary shell latticed, large (up to 0.5 inner zone of cortical shell), stoutly elliptical (short axis 0.87 long axis) as is cortical shell, but with smooth surface, and from its polygonal framework arise radial wirelike threads which compose the outer of the three shells; inner medullary shell more nearly spherical than others; with a stout framework, from each of the 2 opposite poles of this shell arises a very stout, single rod which continues through other outer shells to the exterior as polar spine, and lateral to this strong radial beam are a number of more delicate radial beams; polar spines equal, at right angles to long axis of ring, (that is, the narrow axis of the ring is the morphological polar axis and the spine bearing ring is lateral) polar spines bifurcate distally to form ring; ring, in the most symmetrical and perfect specimens, narrowly elliptical (roughly the short axis about 0.4 long axis in breadth), sides of ring subparallel for most of length and arched, subtriangular at ends, composed of a continuous prismatic beam (triangular in section wIth base faced inwardly), generally the two opposite lateral hoops formed by the ring alike (but not invariably so), and narrower across polar spines than half way distally where there is some expansion; at extreme ends of arched ends of each opposite hoop formed by ring a long (length up to almost 0.3 total breadth of long axis), triangular (not over 2°), apically blunted spine, this spine although variable never very short; pores of outer medullary shell subbexagonal, of neariy similar size and form, with delicate frames from angles of which arise radial elements of the outermost shell (sepaloid threads), pores numbering perhaps as many as 30 across one face of short axis, pores of inner medullary shell larger also hexagonal, with much heavier polygonal frames.

      Length, total (morphological transverse axis of whole), up to 600µm, of lateral spine, up to 150µm, of short axis across polar spines, 120µm, diameter, of cortical frothy shell, up to 100µm, of outer latticed medullary shell, (major axis), 77µm, of inner medullary shell, 36µm.
Repository:Slides Nos. 34522, 34545. [? Museum of Paleontology, University of California at Berkeley]
Type locality:Limestone from the top of a series of shales near Tesla (Mitchell Ravine, left bank of the Corral Hollow Creek, east of Tesla) California.
Original stratigraphic range:Campanian, Senonian Upper Cretaceous, Mesozoic.
Etymology:[No information given]
Subsequent descriptions:?

Literature cited:- Campbell, A. S. and B. L. Clark (1944b). Radiolaria from Upper Cretaceous of Middle California. Geological Society of America Special Paper 57: 1-61.