64 PROTOZOA. 



Sometimes its growth was very regular, but sometimes extremely 

 irregular. The chambers are more or less perfectly marked off 

 from one another by inflections of the test or " septa," per- 

 forated for the passage of bands of sarcode, by which the 

 chambers are brought into organic connection. The sarcode 

 occupying the tiers of chambers is bounded by a thin "proper 

 wall" (fig. 10, a a), perforated by numerous minute tubes by 

 which the pseudopodia reached the exterior. It is obvious, 

 however, that only the chambers of the uppermost tiers could 

 thus have the power of giving out pseudopodia. The various 

 tiers of chambers are connected with one another by a canal- 

 system, and are separated from one another by the develop- 

 ment of supplementary layers of calcareous matter, constituting 

 what is called the " intermediate skeleton." Eozoon appears 

 to have grown in reef-like masses, often of very great extent, 

 and it finds its nearest living allies in the recent Polytrema and 

 Carpenteria. Its shell-structure also shows points of affinity 

 with the extinct Nummulites and the recent Calcarina. Eozoon 

 has been detected, not only in the Laurentian series of Canada, 

 but in other rocks supposed to be of the same age in Bavaria 

 and in other parts of Europe. It also occurs in the Lower 

 Silurian marbles of Connemara in Ireland ; and it is said to 

 have been detected in rocks of Liassic age. 



Having given a somewhat detailed account of the singular 

 Eozoon justified by its importance it will not be necessary 

 to speak at any length of the more modern representatives of 

 the order. In the Silurian Rocks remains of Foraminifera 

 have been detected in various localities, some of the forms 

 apparently being identical with existing types. Thus, Ehren- 

 berg showed that the Lower Silurian sandstones of the 

 neighbourhood of St Petersburg contained casts of Forami- 

 niferous shells in glauconite, some of which were referable 

 to the living genera Rotalia and Textularia. Over wide 

 areas in the Southern Alps, Russia, Spain, Armenia, and the 

 United States, beds of Carboniferous limestone are charged 



with the shells of Fusnlina 

 (fig. n). Whole beds are 

 made up of the remains of 

 this minute fossil, and the 

 Fusulina limestone has been 

 Fig. n.-F***u*a cyiindrica. justly paralleled with the 



Carboniferous, Russia. NummulitlC Limestone of 



Eocene times. 



In the Secondary Rocks, Foraminifera occur in great abun- 

 dance, but they are not specially noticeable except for the part 



