42 THE ROTALIA BECCARIL PART in. 



sand, but with a good microscope the pores may be 

 seen between them. 



The sarcode segments of the animal perfectly corre- 

 spond in shape and in alternate arrangement with the 

 segments of the shell, and are connected by bands of 

 sarcode passing through the crescent-shaped apertures 

 by which each chamber communicates with that which 

 precedes and follows it. 



The Textularise are among the most cosmopolitan of 

 Foraminifera ; some of their forms are found in the 

 sands and dredgings from all shores, from shallow or 

 moderately deep water. In time they go back to the 

 Palseozoic period. 



The Eotalia Beccarii, common on the British coast, 

 affords a good example of the supplemental skeleton, a 

 structure peculiar to some of the higher vitreous Fora- 

 minifera. It has a rather compressed turbinoid form 

 with a rounded margin. Its spire is composed of a 

 considerable number of bulging segments gradually 

 increasing in size, disposed with great regularity, and 

 with their opposed surfaces closely fitted to each other. 

 The whole spire is visible on the exterior, with all its 

 convolutions, and on account of the bulging form of the 

 segments, their lines of junction would appear as deep 

 furrows along the whole spire, were they not partly or 

 wholly filled up with a homogeneous semi-crystalline 

 deposit of shell-substance, which is very different in 

 structure and appearance from the porous shell wall of 

 the segments. 



The genus Calcarina is distinguished by a highly 

 developed intermediate skeleton with singular out- 

 growths, which is traversed by a system of canals ; 

 through these the animal sends its pseudopodia into the 

 water for food to nourish the whole. 



A homogeneous crystalline deposit invests almost 

 the whole of the minute spiral shell of a, Calcarina, 



