188 THE FOEAMINIFEEA 



shallow-water sands and dredgings off; the coasts of 

 the British Islands and elsewhere. The geographical 

 distribution of this particular form is very extensive 

 in the seas of the present day. It is not confined to 

 shallow water, but has a range from the littoral zone 

 down to 2,750 fathoms. Silurian to Uecent. (Plate 

 10, fig. E.) 



L. marginata, Walker and Boys, ' Test. Min.'' 

 1784, p. 2, pi. i. fig. 7. 



Of the compressed varieties of Lagena with an 

 entosolenian orifice this present form may be con- 

 sidered typical. The flange-like border or keel varies 

 greatly in width, and is sometimes so developed that 

 it forms an encircling wing. 



L. jiiargmata,like the preceding, has an extensive 

 geographical distribution ; and is found at all depths 

 from shallow water down to 3,125 fathoms. TJpj^er 

 Cretaceous (GauU) to Becent. (Plate 10, fig. F.) 



Sub-family 2. NoDOSAEnN^E. 



Test polythalamous ; straight, arcuate, or plano- 

 spiral. 



Genus Nodosaria, Lamaegk. 



Test straight or curved, circular in transverse 

 section; aperture typically central. Cambrian to 

 Becent. 



Example. — N. Zippei, Eeuss, ' Yerstein. bohm. 

 Kreidef.' pt. 1, 1845-6, p. 25, pi. viii. figs. 1-3. 



Many of the true forms of Nodosaria are variously 



