260 FORAMINIFERA 



KEY TO THE GENERA 



I. Test of numerous chambers. 



A. Chambers biserial throughout Pleurostomella. 



B. Early chambers biserial, later uniserial. 



1. Completely involute in the adult Ellip^ohulimina. 



2. Not completely involute. 



a. Later chambers forming an elongate test. .. .Nodosarella. 



b. Later chambers forming a glanduline test. 



Ellipsojdeiirostomella. 



C. All chambers uniserial. 



1. Not involute. 



a. Test not compressed, aperture semielliptical. 



Ellijjsonodosaria. 



b. Test not compressed, aperture broad with a large flat 



tooth Plerirostoviellina. 



c. Test compressed, aperture elliptical Ellipsolingulina. 



2. Partially involute. 



a. Test not compressed, aperture semielliptical. 



Ellipsoglandulina. 

 h. Test somewhat compressed, aperture elliptical. 



Gonatosphaera. 



3. Completely involute Ellipsoidina. 



IL Test monothalamous Ellipsolagena. 



Genus PLEUROSTOMELLA Reuss, 1860 



Plate 38, figure 1 

 Genotype, by designation, Flenrostowclla subnodosa Reuss 



Pleurostomella Reuss, Sitz. Akad. Wiss. Wien, vol. 40, 1860, p. 203. 

 Nodosaria (part) Reuss, 1850. 

 Dentalina (pai^t) Reuss, 1850. 



Test usually elongate, biserial; wall calcareous, perforate; 

 aperture, an arched opening on the inner side of the chamber, 

 partially closed by two broad teeth at either side at the base 

 with a narrow vertical slit between. 



Cretaceous to Recent. 



See Cushman and Harris, Notes on the Genus Pleurostomella 

 (Contr. Cushman Lab. Foram. Res., vol. 3, 1927, pp. 128-135, 

 pi. 25). 



