ORDKH 



FORAMINIFERA 



made up of Miliola remains ; at the present day calcareous deposits are being 

 formed by Biloculina in the North Sea west of the coast of Norway. Miliohi 

 begins in the Triassic, and attains its maximum development in the Tertiary 

 and Recent periods. 



fubtdaria, Defr. (Fig. 26). Like Biloculina, but relatively larger. Oral 

 aperture sieve-like ; chambers not hollow, but filled with porcellaneous cal- 

 careous matter, and perforated by numerous anastomosing canals which run 

 parallel with the axis of convolution. Abundant in Eocene of the Paris 

 l.asin. 



Vertebralina, d'Orb. (Fig. 27). Test consisting of coil-shaped loops at 

 commencement, afterwards becoming rectilinear. Tertiary and Recent. 



Sub Order D. VITRO-CALCAREA. Schwager. 



Test calcareous, vitreous, perforate ; more rarely silicious, or silicious with vitro- 

 perf orate substratum ; punctured by numerous fine tubules for the emission of pseudo- 

 podia. Silurian to Recent. 



Family 1. Lagenidae. Carpenter. 



Test perforated only by very fine and closely-set tubules, without supplemental 

 skeleton or canal system. 



Lagena, Walker (Fig. 28, A). Test single-chambered, spherical, ovate, 

 or flask-shaped, with terminal oral aperture. Silurian to Recent. 



Nodosaria, Lam. (Fig. 28, B). Test rod-shaped ; chambers arranged in a 



FIG. -2S. 



.1, I.iii,,<ii,i semtitriata, Williamson. Antwerp Crag (Pliocene); Antwerp. B, Nodosaria spinieosta, cl'Orb. 

 'IViM (Miocene) ; Baden, near Vienna. C, Dentalina eleyans, d'Orb. Same locality. D, Cristrllarin rt idnta, Lam. 

 Srapliiti'n-Hiincr (Turonian) ; Bohemia. E, Vagimdina recta, Reuss. Neocomian ; Salzgitter, Hanover. F, 

 J.liiiiiiliiin 1-1,,-ifntn, d'Orb. Tegel (Miocene) ; Baden, near Vienna. 



straight line and set off from one another by constrictions ; oral aperture 

 round, terminal. Widely diffused from Silurian to Recent. 



Dentalina, d'Orb. (Fig. 28, (7). Like the preceding, but slightly bent. 

 Carboniferous to Recent. 



Vaginulina, d'Orb. (Fig. 28, E). Test straight, laterally compressed; 

 segments flattened, with obliquely directed septa. Triassic to Recent. 



Marginulina, d'Orb. Early segments curved or helicoid, later ones rec- 

 tilinear. Oral aperture slit-like. Triassic to Recent. 



Oristellaria, Lam. (Fig. 28, D). Test regularly piano-spiral, with convolu- 

 tions completely enveloping one another. Oral aperture round. Triassic to 

 Recent. 



