REPORT OF THE DIRECTOR I918 I 65 



aperture. The shell is finely punctate and delicate in segmentation; 

 and cross sections of this genus can be separated from the more 

 common textularian type, even though the distinctive feature of 

 the aperture is lacking. 



This type is one of the oldest of all Foraminifera and was described 

 by Ehrenberg from the ''Silurian Clay" of St Petersburg, now 

 known to be of Lower Cambrian age. We identify two types of 

 this genus in the Bonaventure chert, but they are not typical of 

 either species to which they are assigned. The shorter, widely 

 expanding form may possibly be new; this is discussed under the 

 description of the form. One of these spedes, B. reticulata 

 Hantken, was found in strata of Triassic age and described by 

 Vadasz in his report on the Trias Foraminifera from Bakony. 



Bolivina dilatata Reuss 



Plate 3, figures i, 2 



Bolivina d i 1 a t a t a Reuss, 1849, Denkschr. Akad. Wiss. Wien, i: 



381, pi. xlviii, fig. 15 

 Bolivina dilatata Goes, 1894, K. Sv. Vet. Akad. Handl., v. 25, 



no. 9, p. 50, pi. ix, figs. 482-86 

 Bolivina dilatata Brady, Parker & Jones, 1888, Trans. Zool. Soc, 



12: 221, pi. xliii, figs. 3 and 6 



We find on slide 6 a short, widely oval, few-chambered Bolivina. 

 This type does not correspond exactly with any published figures 

 as far as we are aware for several reasons, and we are inclined to 

 consider it a new type. The form nearest to this species, so far 

 as we know, is Bolivina reticulata Hantken . It also 

 resembles closely in outline B . tenuis, Brady (Challenger 

 Report), but the latter has a complex internal segmentation not 

 present among simple bolivine forms. The B. dilatata of 

 the texts has many chambers, and it expands toward the distal 

 chamber like a Textularia, to which genus Bolivina is related. The 

 segments are not quite complete and sure of identification so that 

 it is difficult to place this form with certainty. The gracefully 

 arched segments narrow toward the margin, and this constriction 

 is not so marked inB. dilatata. 



It is more likely that this is a primitive type of form which devel- 

 oped into symmetrical, elongated, rapidly widening Bolivinae of 

 later geologic horizons. The form would merit a new name if the 

 surface features and full structure could be made out. The distal 

 end is sharp and almost apiculate; the anterior, well rounded, oval 

 and measures 0.18 mm in length and 0.16 mm in width, which is 



