FORAMINIFERA OF THE ATLANTIC OCEAN 81 



Family 35. CALCARINIDAE 



Test trochoid in the early stages, soon adding a supplementary mass 

 of shell material over which the new chambers are added, in the higher 

 genera the chambers extending to the dorsal side and finally covering 

 the whole test in a globular series, the test developing bosses of shell 

 material which are the surface end of pillars, and large spines inde- 

 pendent of the individual chambers; wall calcareous, coarsely per- 

 forate; aperture in the early trochoid stages like Rotalia, later con- 

 sisting of numerous smaller openings; supplementary canal system 

 well developed. 



This family which developed from the spinose forms of Rotalia 

 shows a progressive complexity of structure from the simpler Cal- 

 carina to the complex Baculogypsina. The large spines are developed 

 early and are one of the striking characters of the family. The 

 •species of the various genera are characteristic of warm shallow waters, 

 at the present time in the Indo-Pacific. 



Genus CALCARINA d'Orbigny, 1826 



Calcarina d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 276.— H. B. Brady, 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 711. — Chapman, The 

 Foraminifera, 1902, p. 223. — Cushman, Special Publ. No. 1, Cushinan 

 Lab. Foram. Res., 1928, p. 282. 



Nautilus (part) of Authors. 



Genotype, by designation. — Nautilus spengleri Linnaeus. 



Test trochoid, biconvex, with radial spines independent of the 

 individual chambers, usually in the plane of coiling, in the early 

 stages with the test simple, later with a supplementary mass of shell 

 material over which the new chambers are laid on the ventral side; 

 wall calcareous, perforate, with pillars; aperture in the adult typically 

 a row of small openings along the inner ventral margin of the chamber. 



Cretaceous to Recent. Living only in the Indo-Pacific. 



Genus SIDEROLITES Lamarck, 1801 



Siderolites Lamarck, Syst. Anim. sans Vert., 1801, p. 376. — Cushman, 



Special Publ. No. 1, Cushman Lab. Foram. Res., 1928, p. 284. 

 Siderolina Defrance, Diet. Sci. Nat., vol. 32, 1824, p. 180. 

 Calcarina (part) of Authors. 



Genoholotype. — Siderolites calcitrapoides Lamarck. 



Test in the early chambers similar to Calcarina, spines later added 

 at right angles to the peripheral ones, chambers soon covering the 

 dorsal side; wall calcareous, perforate, with pillars in some species 

 ending at the surface in raised bosses; aperture in the adult at the 

 basal edge of each chamber, finally represented by the larger circular 

 openings of the chamber wall. 



Cretaceous to Recent. Living only in the Indo-Pacific. 



