REPORT OF THE DIRECTOR I91S 161 



mina has never been so reported. Without the position and shape of 

 the aperture such types could not be separated in rock slides. 



The best illustrations of the genus are found on slides 2,3,4 and 5 

 (X) . On slide 5 the form is cut vertically and reveals a partial seg- 

 ment at both extremities; the separation and size of the segments 

 are very suggestive of Verneuilina. 



Genus BULIMINA d'Orbigny 



The genus Bulimina consists of an elongated, spiral textularian 

 form in which the final segments are large and overlapping and its 

 serial development never symmetrical as in its related subvarieties 

 Virgulina and Bolivina. This form has been identified in the Triassic 

 and every succeeding formation, but it increases in the Tertiary 

 where many species are known. We do not find this genus, however, 

 recorded in Lower Paleozoic strata; but, since both its relatives 

 Virgulina and Bolivina occur rather frequently in these cherts, it is 

 not at all unlikely that the irregularly-built Buliminae are also present. 

 We find a few sections quite similar to those Buliminae inhabiting 

 Arctic waters today, but they are small, somewhat imperfect and 

 very difficult to be positive about. Bulimina shows more sphaeroidal 

 segments than its congenitor Virgulina, so well developed on slide 2 . 

 The walls of both these genera are thin, hyaline and originally must 

 have resembled those of the Cretaceous varieties- which we would 

 expect to exist in rather deep water. These are, however, much 

 smaller than the usual fossil types, the specimen we provisionally 

 place under B. p y r u 1 a measuring but 0.08 mm in length. 



Bulimina pupoides d'Orbigny 



Plate 2, figures 3, 4 



Bulimina p u p o i d e s d'Orbigny, 1846, Foram. Foss. Vienne, p. 185, 



p. xi, figs. 13, 14 

 Bulimina pupoides Williamson, 1858, Recent Foram. Great Britain, 



p. 62, pi. V, figs. 124, 125 

 Bulimina pupoides, Bagg, 1905, U. S. Geol. Survey, Bui. 268, p. 22, 



pi. iii, fig. 2 



Bulimina pyrula has been reported from the Trias but 

 we do not know of an earlier occurrence of the genus Bulimina. . 

 It is possible that we have wrongly identified Bulimina 

 pupoides d'Orbigny, which appears in transverse section on 

 slide 2 (see also slide i), as no triserial, bulimine type can be satis- 

 factorily determined in cross section. However, the form in question 

 shows bulimine growth, overlapping, shortened segments with 



