112 



section, fig. 3, c, corresponding with the portion 2, c, in the verti- 

 cal section. Here we find that the pseudopodian tubes are wanting, 

 excepting in the innermost layers (3, d), where they are visible ; but 

 the outer layers, corresponding with the translucent triangular 

 spaces (fig. 2, c c') are (perforated in every direction by a net-work 

 of minute anastomosing canals, which communicate freely with the 

 exterior of the shell, through numerous minute apertures. They 

 also give off branches, which pass between the two layers of which 

 each septum consists. As far as I can ascertain, however, these lat- 

 ter branches, though visible throughout the section, are most con- 

 spicuous at the points of junction, where the two divergent layers of 

 each septum unite with the external parietes of the shell. 



What special function these canals have been designed to fulfil, 

 I am wholly unable to determine. The greater portion of the septa 

 between which some of the branches pass, exhibit no traces of fora- 

 mina ; otherwise, we might regard them as being destined to bring 

 an additional supply of aqueous fluid into contact with the internal 

 soft organism. But where the thin adjacent parietes are so freely 

 supplied with true pseudopodian tubes, it is difficult to conceive that 

 any necessity exists for such a provision. 



The next structure to which I would direct attention, is that 

 found in what I believe to be an undescribed species of Nonionina. 

 I am indebted to Mr. Matthew Marshall, of the Bank of England, 

 for supplies of several beautiful sands, teeming with exquisite orga- 

 nisms. Amongst others, there was one from Manilla, which con- 

 tained numbers of a fine form of Nonionina. In this shell all the 

 septa are rendered distinctly visible externally by the marked con- 

 trast which exists between their solid, and consequently translucent 

 texture, and the more opaque, yellowish-white parietal tissues, in 

 which the foramina occur. Another feature characterizing the orga- 

 nism, and of which I had previously seen no recent example, was 

 found in its thickened peripheral margin. 



On making a vertical section, the instructive appearances repre- 

 sented by fig. 4 presented themselves. In the centre we find the 

 primordial globular cell (4, a), apparently common to all the Forami- 

 nifera. On each side of this cell, we have the sections of three spiral 

 convolutions ; the outermost one on each side preserving an almost 

 perfect transverse septum. The one to the left exhibits, at the point 

 4, 6, the large central aperture of the Nonionina ; in addition to 

 which, we find a few very small and irregularly distributed perfora- 

 tions, which do not exist in the ordinary types of the genus. 



