﻿TRUNCATULINA. — PULVTNULINA. 



139 



Truncatulina Boueana, d'Orbigny. PI. VI, fig. 11. 



Truncatulina Boueana, d'Orbigny, 1846. For. Foss. Vienne, p. 169, pi. ix, figs. 



24—26. 



Characters.— Test suborbicular, depressed, rugoso-punctate ; superior surface 

 complanato-concave; inferior, convex, slightly excavated at the umbilicus; segments 

 nine in number, complanate, arcuate ; margin somewhat limbate. Diameter ^ inch 

 (0-33 mm.). 



The above description is a mere English rendering of d'Orbigny's words, excepting 

 in the transposition of the terms " superior " and " inferior," on the grounds set forth in 

 a former page. One or two minute Truncatulina from the Belgian Carboniferous beds 

 answer so exactly to the description of Tr. Boueana and to the figures given in the 

 "Vienna Basin" monograph, that, notwithstanding the difference of geological age, 

 they must be treated as representatives of that form. They correspond even in 

 dimensions and number of visible chambers. There is not much in the name, for 

 after all Truncatulina Boueana only represents a neatly made, small sub-variety of 

 Tr. lobatula, having an even margin, with the later segments slightly embracing on the 

 superior surface; but, as the only specimens found have the characters assigned to this 

 particular form, it seems best to retain the trivial appellation. 



Distribution.— It would, I suspect, be impossible to define the distribution of this 

 variety, as distinct from Tr. lobatula, in the Tertiary microzoic rocks or in the living 

 condition. In the Carboniferous beds it is represented by a very few specimens from 

 the Calcaire de Namur of Belgium. 



Genus — Pulvinulina, Parker and Jones. 



Hammoni^;, Nautili, Soldani. 

 Nautilus, Fichtel and von Moll. 

 Pulvinulus, Placentula, Lamarck. 

 Eponides, Cancris, CidarollUs, de ITontfort. 

 Crepidulina (in part), Rotalites (in part), Defiance. 

 Eotalta (in part), d'Orbigny, Reuss, Ehrenberg, Schwaoer. 

 Rotalina (in part), d'Orbigmj, Reuss, Egger, Williamson, Parker and Jones 

 Pulvinulina, Parker and Jones, Carpenter, Reuss, Karrer, Bradg, Giimbel, Sars, Vanden 

 hroeck. 



