ORDER n FORAMINIFERA 29 



Clwiacammina Brady (Crihrostomum Moller), (Fig. 15, C, D). Test 

 arenaceous with calcareous basis. Chambers biserial, rectilinear. Oral aper- 

 ture jiorous. Abundant in Carboniferous Limestone (cf. Bigenerina d'Orb.). 



Subfamily C. Verneuilininae Cushman. 

 Test at first triserial, later biserial or even uniserial in some genera. 



Gaudryina d'Orb. (Fig. 14, E). Test free, early portion triserial, later 

 chambers arranged biserially, wall usually arenaceous. 



Clavulina d'Orb. (Fig. 14, F). Test at first triserial, latest developed 

 portion uniserial. Eocene to Recent. 



Valvulina d'Orb. (Fig. 15, U). Test arenaceous with calcareous basis. 

 Chambers in triple series arranged in screw-like spiral. Carboniferous to 

 Recent. 



Tetrataxis Ehrbg. (Fig. 15, F). Test calcareous, conical. Alternating 

 chambers arranged in a turbinate spire. Carboniferous Limestone. 



Subfamily D. Bdlimininae Brady. 



Test composed of chambers in an elongate spiral, aperture elongate, loop-shaped, 

 usucdli/ oblique, test calcareotis, hyaline in young. 



Bulimina d'Orb. > (Fig. 15, A, B). Test calcareous, the alternating 

 chambers arranged in an elongated spire. Triassic to Recent. 



Subfamily E. Cassidulininae Brady. 



Test with the chambers biserial but combined with a spiral or volute arrangement 

 making a complex test. 



Ehrenbergina Henss (Fig. 15, G). Test calcareous, the alternating biserial 

 segments either completely or only partially coiled. Tertiary and Recent. 

 Oassidulina d'Orb. Tertiary and Recent. 



Family 5. Chilostomellidae. 



Test calcareous, finely perforate, composed of numerous chambers, following each 

 other from the same end of the long axis, or alternately from the two ends, or 

 in cycles of three. 



The genera Ellipsoidina Seg., Chilostomella and Allomorphina Reuss compose 

 this family. Cretaceous to Recent. 



Family 6. Lagenidae Carpenter. 



Test calcareous, vitreous, finely perforated, one or more chambers placed in a 

 straigld line, coiled or variously arranged. 



Subfamily A. Lageninae Brady. 



Test monothalamous, flash-like. 



Lagena Walker (Fig. 16, A). Test single-chambered, spherical, ovate or 

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



