264 Transactions of the Royal Microscopical Society. 



and all. If I liave rightly interpreted the appearances to indicate 

 foramina at all, then of course the nature of these bodies is settled. 

 What else can the appearances be due to ? The action of polarized 

 light has something to say about this. Seen in this way, the shell 

 is divided into a number of compartments separated by irregular 

 lines. These lines, then, seem to be cracks, or the boundaries of 

 irregular crystallization ; at least there is nothing in the appearances 

 to prove they are not, and the whole shell seems so altered by meta- 

 morphic crystallization as to render it doubtful how far any speci- 

 men shows the original structure. One specimen, in which the 

 whole interior was filled with black dust, showed little perforations 

 of the shelly but they were so irregular and of such various sizes 

 as to make it as likely as not they were due to metamorphism 

 rather than structure. We are therefore cautioned that anything 

 but what cannot possibly be other than true structure may possibly 

 be due to some subsequent alterations, and therefore be deceptive. 

 Nevertheless, their behaviour under polarized light is very similar 

 to that of Foraminifera, and it would be, I think, difiicult to prove 

 most of the fossil Foraminifera such by the demonstration of their 

 foramina, only we do not attempt it because we recognize them by 

 their shape. 



In the present case we do not recognize the shape, but there 

 is nothing in it to prevent their being Foraminifera. They 

 have only one cell, no partition occurring inside. They have no 

 large aperture, but neither has the Orhnlina or the Globigerina in the 

 majority of cases. The general resemblance, in fact, of these shells 

 in point of structure to that represented by the fossil Orhulinse in 

 similar strata, inclines me strongly to the belief that the foramini- 

 feral interpretation is the right one, that they belong to the per- 

 forate group, and should be placed near the last-named genus. 

 They have a general resemblance in shape to the Noctiluca, and 

 the lines on their surface which are distinguishable in most, if they 

 be not due to crystallization renders the similarity greater; but 

 besides this, no organism that I can think of gives any example of 

 such a form. 



I take them, therefore, to be a peculiar form of Foraminifer, 

 very characteristic of corallian strata, and would propose to name 

 them Renulina from their shape, and for a specific name Sorhyana 

 from their original discoverer. 



