FORAMINIFERA 



347 



lies, and lists one genus as an example for each, but places Gromia 

 and allied genera in the order Testacea (p. 323). 



Fig. 158. a, Rhahdammina abyssomm, X5 (Ktihn); b, Rhizammina 

 algaeforniis, fragment of, Xl4 (Cushman); c, Saccavimina sphaerica, 

 X8 (Rhumbler); d, Hijperammina subnodosa, X4 (Brady); e, Ammo- 

 discus incertus, X20 (Kiihn); f, Silicina liynitata, Xl3 (Cushman); 

 g, Reophax nodulostis, X3 (Brady). 



Test entirely or in part arenaceous 



Test single-chambered or rarely an irregular group of similar 

 chambers loosely attached 

 Test with a central chamber, 2 or more arms; fossil and recent 

 Family 1 Astrorhizidae 



Genus Rhabdammina Sars (Fig. 158, a) 



Test without a central chamber, elongate, open at both ends; 

 fossil and recent Family 2 Rhizamminidae 



Genus Rhizammina Brady (Fig. 158, b) 



Test a chamber or rarely series of similar chambers loosely at- 

 tached, with normally a single opening; fossil and recent. . . 

 Family 3 Saccamminidae 



Genus Saccammina Sars (Fig. 158, c) 



Test 2-chambered, a proloculum and long undivided tubular second 

 chamber 

 Test with the second chamber, simple or branching, not coiled; 

 mostly recent and also fossil .... Family 4 Hyperamminidae 



