327 



shell is the habitation of a number of individuals living socially 

 together within a common investment after the manner of the 

 Polycyttarian Radiolaria. This, of course, is wholly incorrect ; 

 the Foraminifera whether unilocular or multilocular, are ''indi- 

 viduals," and the successive segments have no more separate 

 existence than the leaves on a plant, though, like them, they 

 might under favourable conditions reproduce their kind. 



The classification adopted is in the main that of Brady, but 

 certain alterations have been made in the arrangement of the 

 families with very questionable advantage. 



The rearrangement of the families appears to be due to the 

 author's views on the value of the arenaceous test as a distinctive 

 mark, although the general tendency of modern research has 

 been to minimise its importance. 



As regards the illustrations, which are all reproduced by process 

 on a black ground from actual photographs of the foraminifern,, 

 nothing but satisfaction can be expressed. With the exception 

 of the Challenger report there is no recent work on the 

 Foraminifera so profusely, and on the whole, so admirably illus- 

 trated as this. The uniform magnification of 15 diameters 

 adopted for all the species, although somewhat of a drawback as 

 regards the minuter forms, gives a general idea of the relative 

 dimensions of the several species which cannot but be of value to 

 the young student. We believe that this is the first occasion on 

 which direct photographs of foraminifera have been used, at any 

 rate to such an extent, for the purposes of illustration, and any 

 microscopist will appreciate the difficulty of successfully photo- 

 graphing such thick and solid opaque objects. It is therefore 

 sufficient to remark that, with very few exceptions, the figures are 

 all that could be desired, the contour, markings and nature of 

 the test being clearly distinguishable, while in some of the best 

 illustrations the texture and the hyaline transparency are repro- 

 duced with a faithfulness which no engraving or lithograph could 

 equal. A. E. 



