46 MICROSCOPICAL OBJECTS FOUND 



perforations leave no doubt as to its being one 

 of the Foraminifera. I shall afterwards have to 

 notice a similar form found in the Lias by Mr. 

 Strickland. 



Fig. 35 represents the inferior surface of a 

 Truncatulina, which I believe to be the T. tuber- 

 culata, a complete cosmopolite. The channel of 

 communication between the cells is most distinctly- 

 seen along the umbilical margin of the outer ones. 



Figs. 36, 37, and 38 represent various forms of 

 the family of Plicatilia of Ehrenberg, the Miliolaj 

 of older authors. The two former belong to the 

 genus Spiroloculina (D'Orbigny). Fig. 38 is, 

 apparently, a Biloculina, — 38, a, exhibits it as 

 an opaque, — and 38, b, as a transparent object. 

 The singular forms of the MiliolsB occur at 

 the present time in sand brought from most 

 parts of the world. They are abundant on 

 our own shores. I have received them from 

 the West Indies, the Phillipine Islands, and a 

 variety of other distant localities, whilst we shall 

 find that analogous genera constitute the greater 

 portion of some tertiary deposits. They are not 

 found in rocks coseval with, or older than the 



