582 DE. CARPENTER'S RESEARCHES ON THE PORAMINIFERA. 



tion in this group is not confined to the present epoch, but that it is true also of the 

 Foraminiferous fauna of all the geological periods to which their researches have 

 extended. " Our own experience of the wide limits within which any specific group of 

 the Foraminifera multiply their varietal forms, related by some peculiar conditions of 

 growth and ornamentation, has led us to concur fully with those who regard nearly 

 every species of Foraminifera as capable of adapting itself, with endless modifications of 

 form and structure, to very different habitats in brackish and in salt water, in the 

 several zones of shallow and abyssal seas, and under every climate, from the Poles to 

 the Equator. In arranging our synoptical tables of the Mediterranean Rhizopoda, recent 

 and fossil, and in comparing their numerous specific and varietal forms one with another, 

 we have not confined ourselves to our collections from this region, but have necessarily 

 made comparisons of forms from almost every part of the globe, from the Arctic and 

 the Tropic Seas, from the temperate zones of both hemispheres, and from shallow as 

 well as deep-sea beds. Geologically, also, we have reviewed the Foraminifera in their 

 manifold aspects, as presented by the ancient Faunas of the Tertiary, Cretaceous, Oolitic, 

 Liassic, Triassic, Permian, and Carboniferous times ; finding, to our astonishment, that 

 scarcely any of the species of the Foraminifera met with in the Secondary rocks have 

 become extinct ; all, indeed, that we have yet seen have their counterparts in the recent 

 Mediterranean deposits. This is still more clearly found to be the case with regard to 

 the Chalk of Maestricht and the Tertiaries*." 



258. The same excellent observers, in summing up their description of the Forami- 

 nifera of the blue clay met with in the alabaster pits at Chellaston near Derby, 

 belonging to the Upper Triassic series, thus express themselves : " Having thus 

 pointed out that, judging from these specimens obtained at Chellaston, the minute 

 Nodosarince and other Foraminifera of the Triassic period have continued to exist 

 through the intermediate ages to the present day without losing any of their essentially 

 specific features, we will observe that the Nodosarias are present in rocks of still greater 

 age than the Trias, namely, the Permian and Carboniferous, and probably even the 

 Lower Silurian. Nodosarice and Dentalince abound in some of the Permian limestones 

 of Durham and the Wetterau in company with Textularice. Nodosaria occurs also in 

 the Carboniferous Limestone of Ireland, according to M'Coy ; and the green sand of the 

 Lower Silurian series near St. Petersburg has granted to EHRENBEBG casts of chambers 

 something like those of Dentalina, together with unmistakeable casts of Textularian and 

 Rotalian shells. We may remark, too, that the Fusulina of the Russian, North American, 

 and Arctic Mountain limestone carries back the pedigree of the Nonionina group to the 

 paleozoic periods, and that it is accompanied with other Foraminifera of known types, 

 among which Nummulina is not absent. This last-named type has rare representatives 

 in the Lias and Oolite ; it acquired great potency in the Tertiary seas, and is not extinct 

 now. Altogether we have here some remarkable instances of the persistency of life- 

 types among the lower animals. Though the specific relations of the Paleozoic Forami- 

 * Quarterly Journal of the Geological Society, August I860, p. 294. 



