FAMILY 10. VERNEUILINIDAE 127 



Genus HETEROSTOMELLA Reuss, 1865 



Plate 12, figure 8; plate 13, figure 18 

 Genotype, by designation, Gaudryina siphonella Reuss 



Heterostomella Reuss, Sitz. Akad. Wiss. Wien, vol. 52, pt. 1, 1865, p. 448. 

 Gaudryina (part) Reuss, Zeitschr. deutsch. Geol. Ges., vol. 3, 1851, p. 78 



(and later authors). 

 Plectina Marsson, Mitth. Nat. Ver. Neu-Vorpommern u Riigen, Jahrg. 



10, 1878, p. 160 (genotype, by designation, Gaudryina ruthenica 



Reuss). 



Test with at least the early stages triserial, later biserial ; wall 

 arenaceous ; aperture in the young as in Gaudryina, later with a 

 terminal aperture with a neck and occasionally a slight lip. 



Cretaceous to Recent. 



Genus TRITAXILINA Cushman, 1911 

 Plate 12, figures 9-11; plate 13, figure 19 



Genoholotype, Clavidina caperata H. B. Brady 



Tritaxilina Cushman, Bull. 71, U. S. Nat. Mus., pt. 2, 1911, p. 71. 

 Clavulina (part) H. B. Brady, Quart. Journ. Micr. Sci., vol. 21, 1881, p. 



54 (not d'Orbigny, 1826). 

 Tritaxia (part) H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 



p. 390 (not Reuss, 1860). 

 Clavulinella Schubert, Pal. Zeitschr., vol. 3, 1920, p. 181 (genoholotype, 



Clavulina caperata H. B. Brady). 



Test in its early stage triserial, later becoming biserial and 

 finally uniserial ; chambers numerous, distinct, interior labyrin- 

 thic; wall arenaceous; aperture, in the early stages, a narrow 

 opening at the base of the inner margin of the chamber, later 

 becoming terminal and central, with a slight lip, usually with a 

 series of peripheral teeth projecting in and partially closing the 

 opening. 



Eocene to Recent. 



Genus CLAVULINA d'Orbigny, 1826 



Plate 12, figures 12-15; plate 13, figure 17 

 Genotype, by designation, Clavulina parisiensis d'Orbigny 



Clavulina d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 268. 

 VerneuiliTia (part) of authors. 



