NO. 4 FORAMIXIFERA CUSHMAN I9 



part of sand grains, thin, firmly cemented ; aperture formed by the 

 open ends of the tube or in some cases closed anteriorly by a loosely 

 aggregated knob of spicules. 



Genus BATHYSIPHON G. 0. Sars, 1871 

 Plate I, fig. 4 

 Test free, cylindrical, often tapering slightly, straight or more 

 often somewhat curved, in some species externally constricted but not 

 correspondingly constricted internally ; wall composed of a base of 

 broken sponge spicules cemented and overlaid with a fine grained ap- 

 parently siliceous cement, aperture at the ends of the tube. 



Genus RHIZAMMINA H. B. Brady, 1879 



Plate I, fig. 5 

 Test free, consisting of a simple or dichotomously branching, flex- 

 ible tube ; wall largely chitinous, bearing various foreign bodies at- 

 tached to the exterior. 



Subfamily 2. SACCAMMININAE 



Test consisting of a single chamber, or group of superficially 

 attached chambers, the walls made up for the most part of aggluti- 

 nated material ; apertures sometimes numerous but usually single ; 

 tests free or attached. 



Genus PSAMMOSPHAERA F. E. Schulze, 1875 

 Plate I, fig. 6 

 Test free or attached, single chambered, usually spherical, no 

 definite aperture, the pseudopodia making their way out through the 

 interstitial openings between the elements of the test ; wall of sand 

 grains, mica flakes, sponge spicules, or other foraminiferal tests 

 firmly cemented. 



Genus SOROSPHAERA H. B, Brady, 1879 

 Plate I, fig. 7 

 Test consisting of a colony of more or less inflated chambers, 

 without definite apertures, the walls joined to one another, composed 

 of sand grains with interstitial openings. 



Genus DIFFUSILINA Heron-Allen and Earland, 1924 

 Test sessile, squamous, composed of very finely comminuted sand 

 and mud enveloping a thin labyrinthic layer of chambers. External 

 surface smooth and finished, white to gray in color, furnished with 

 a few sparsely distributed pustules of more loosely aggregated 

 material. 



