282 FORAMINIFERA 



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 independent of the individual chambers ; 

 wall calcareous, coarsely perforate; aperture in the early 

 trochoid stages like Rotalia, later consisting of numerous smaller 

 openings ; supplementary canal system well developed. 



Genus CALCARINA d'Orbigny, 1826 



Plate 42, figure 4; plate 44, figure 1 

 Genotype, by designation, Nautilus spengleri Linne 

 Calcarina d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 276. 

 Ncmtihis (part) of authors. 



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. 



EXPLANATION OF PLATE 42 



Amphisteginidae, Calcarinidae 



Fig. 



1. Asierigerina carinata d'Orbigny. X 30. (After type figures). 

 2, 3. Amphistegina lessonii d'Orbigny. Fig. 2 (After type figures). 

 Fig. 3 (After H. B. Brady). X 20. 

 4. Calcarina spengleri (Linne). X 20. (After H. B. Brady). 

 5-7. Siclerolites calcitrapoides Lamarck. (After Hofker). Fig. 5, 

 Exterior. Fig. 6, Section. Fig. 7, Showing structure of interior. 

 8-12. Bacnlogypsina sphaerulatiiH (Parker and Jones). Figs. 8-10 

 (After Carpenter). Fig. 8, Exterior. X 35. Fig. 9, Section. 

 X 8. Fig. 10, Young stage. X 35. Figs. 11, 12 (After Hofker). 

 Young megalospheric specimens. X 80. 

 (In all figures: a, dorsal view; b, ventral view; c, peripheral 

 view). 



