NO. 4 FORAMINIFERA CUSHMAN 29 



Genus TROCHAMMINA Parker and Jones, i860 



Plate 4, fig. 5 



Test free or sometimes adherent, spiral, trochoid, chambered ; all 

 chambers visible when viewed from above, only the chambers of the 

 last-formed volution visible from below ; wall arenaceous usually 

 with considerable cement ; aperture an arched slit on the ventral side 

 of the chamber at its contact with the preceding volution. 



As here considered, Trochammina is restricted to those species like 

 T. inflata (Montagu) or T. squainata Jones and Parker, which have 

 a true spiral, trochoid test with all the chambers visible only from 

 above. 



Genus GLOBOTEXTULARIA Eimer and Fickert, 1899 

 Plate 4, fig. 6 



Test arenaceous, the early chambers in a spire, the later ones 

 irregular, globular, Globigerina-like. 



Genus AMMOCHILOSTOMA Eimer and Fickert, 1899 

 Plate 3, figs. 10, II 



Test free, early chambers spiral, later ones very involute, and 

 the last-formed volution often entirely covering the previously 

 formed chambers and usually at an oblique angle to the earlier 

 growth ; wall arenaceous, with a variable, usually excessive amount 

 of cement ; aperture at or near the base of the apertural face of the 

 chamber, elongate, narrow, color usually reddish or yellowish brown. 



Genus AMMOSPHAEROIDINA Cushman, 19 10 



Plate 4, fig. 7 



Test globose, arenaceous, early portion spiral, later chamber like 

 Sphaeroidina in form, embracing; aperture rounded, at one side of 

 the chamber in the adult. 



Genus SPHAERAMMINA Cushman, 19 10 



Test composed of a series of chambers, the last one formed com- 

 pletely enveloping the preceding ones, but the axis straight ; wall 

 arenaceous. 



Genus AMMOSPHAERULINA Cushman, 1912 



Test spherical, adherent ; wall arenaceous ; composed of two or 

 more chambers, each included by the one next-formed, eccentric ; 

 color light yellowish-brown. 



