REPORT OF THE DIRECTOR I918 1 85 



with Pulvinulina boueana d'Orbigny, which has a larger 

 number of arching segments and which is known as early as the 

 Trias as shown by Vadasz. On slide 3 is a large specimen 0.17 mm 

 in diameter and possessing more septa than the type calls for which 

 we are placing under this species. 



Truncatulina lobatula (Walker & Jacob) 



Plate S, figures loa, &, ii 



Nautilus lobatulus Walker & Jacob, 1798, Adam's Essays, 2d ed., 



p. 642, pi. xiv, -fig. 36 

 Truncatulina 1 o b a t u 1 a Williamson, 1858, Recent Foram. Great 



Brit., p. 59, pi. V, figs. 121-23 



The synonymy of T. lobatula is one of the most extensive 

 among rotaline forms, and includes forms with considerable varia- 

 tion in number of segments, amount of marginal limbation and 

 arching of septae; but its spire is low, superior surface always 

 relatively flat or even slightly depressed and there are from two 

 to three convolutions, the ultimate whorl showing normally about 

 eight chambers. The cross sections of this species, which is rather 

 abundant in the cherts of the Bonaventure formation, show well- 

 pronounced marginal sutures, but the ultimate segment is more 

 regular and gracefully convex than in many modern loose-growing 

 forms. One of these sections on slide i consists of seven, five and 

 two segments and resembles Rosalina simplex d'Orbigny 

 of the Paris Basin Eocene. An excellent section cut on edge (slide i) 

 and shown in figure 10& illustrates the plano-convex character of 

 this interesting foraminiferan which has such a remarkable geographic 

 and geologic distribution. It is reported in the Carboniferous, 

 Trias and every succeeding formation and is widespread in existing 

 oceans. 



The species is probably present in every one of the six cherts 

 studied, but the best and most representative specimens, in addition 

 to those given above, are seen on slide 3, slide 4 and slide 6. 



Truncatulina ungeriana d'Orbigny 



Plats 5, figures 12, 13 



Rotalina ungeriana d'Orbigny, 1846, Foram. Foss. Vienne, p. 157, 



pi. viii, figs. 16-18 

 Rotalia roemeri Reuss, 1855, Sitz. Akad. Wiss. Wien, 18: 240, pi. iv, 



fig. 52 (Typical in segmentation) 

 Truncatulina ungeriana Vadasz, 1910, Triasforam, aus dern Bak- 



ony, p. 32, pi. 2, fig. 6 (Typical of our form) 



