The foraminifera: an introduction to the study of the protozoa . a in any country. The absence ofthese organisms is very remarkable, for the condi-tions under which the deposits of Devonian age withthe marine facies were laid down seem to be espe-cially favourable for the existence of usual concomitants of foraminiferal depositsare greatly in evidence in Devonian rocks, such ascorals, ostracoda, and oolitic-granules, but neverthe-less the Foraminifera are strangely wanting. This singular paucity of Foraminifera in theDevonian strata is strongly emphasised by the appa-rently su
The foraminifera: an introduction to the study of the protozoa . a in any country. The absence ofthese organisms is very remarkable, for the condi-tions under which the deposits of Devonian age withthe marine facies were laid down seem to be espe-cially favourable for the existence of usual concomitants of foraminiferal depositsare greatly in evidence in Devonian rocks, such ascorals, ostracoda, and oolitic-granules, but neverthe-less the Foraminifera are strangely wanting. This singular paucity of Foraminifera in theDevonian strata is strongly emphasised by the appa-rently sudden appearance of a large number of genera 256 THE FOEAMINIFEEA and species in the Carboniferous system. At thisperiod the Foraminifera were so abundant in certainareas that they often formed very extensive example, Saccanimiiia constitutes a large pro-portion of the rock known as the Saccammina lime-stone of England, Scotland, Ireland, and Belgium;and this genus is found throughout the Carboniferousseries, but chiefly near its base. Fusiilina is. Fig. 28.—Saccammina Limestone ; Carboniferous,Northumberland, x Qh. Original. another important genus, forming the main bulkof the Fusulina limestones so extensively developedin the Upper Carboniferous of Russia, China,Japan, and North America; and which also occursin Spain (Cantabrian Chain) and the SouthernAlps (Upper Carniola and Carinthia), the Caucasus,Isle of Chios, Borneo, and Sumatra. The two above-mentioned genera are of fairh GEOLOGICAL EANGE 257 large dimensions; there are, however, many othersin the Carboniferous series which, although smallerin size, are often very numerous, and thereforeimportant as rock-builders. Many of these species,and even genera, are more or less restricted tothe Carboniferous system. Among other Carboni-ferous types we may mention the genera Hcvploplirag-?ninnn^ Stacheia, NodosijieUa, Endotliyra (generally a
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