Plate 4 



GENUS POLYMORPHINA d'oRBIGNY 



Polymorphina communis (d'Orbigny) 



1 Thin section, x 232. (Slide 5 (X)) 



2 Entire specimen, periphero-lateral aspect. (After Bagg, U. S. 



G. S. Bui. 513, 1912, pi. 21, fig. 14) 



Polymorphina compressa d'Orbigny 



3 Entire specimen, x 24. a, front view; h, side view. (After 



Parker and Jones, v. 155, 1865, pi. 13, figs. 47, 49) 



Polymorphina gibba d'Orbigny 



4 Thin section, x 174. (Slide 6) 



5 Entire specimen, x 120. (After Cushman, U. S. G. S. Bui. 676, 



1918, pi. 2, fig. 4) 



GENUS ORBULINA d'ORBIGNY 



Orbulina ovalis Matthew 



6 Thin section, x 116. (Slide 4) 



7 Entire specimen, x 20. (After Matthew, N. Y. Acad. Sci., 



v. 14, 1895, pi. I, fig. 2) 



Orbulina porosa Terquem 



8 Thin section, x 174. (Slide 6) 



9 Entire specimen, diameter 0.32 mm. (After Vadasz, Triasform. 



aus dem Balcony, 1910, pi. i, fig. 30 (in error for fig. 31) 



Orbulina uni versa d'Orbigny 



10 Thin section of single-chambered form, x 116. (Slide 5 (X)) 



11 Entire specimen, x 50. (After Brady, Chal. Rep't, v. 9, 1884, 



pi. 81, fig. 11) 



12 Thin section of double-chambered form, x 116. (Slide 6) 



13 Entire specimen, x 50. (Ref. cit., pi. 81, fig. 20) 



