. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. 292 HISTORICAL PALEONTOLOGY. after the Middle Eocene period. During that period, the sea prevailed where these chains now rise; for Nummulites and their accompanying Testacea were unquestionably inhabitants of salt ; The Ccelenterafes of the Eocene are represented principally by Corals, mostly of types identical with or nearly allied to those now in existence. Perhaps the most characteristic group of these is that of the Turbinolidce, compri
. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. 292 HISTORICAL PALEONTOLOGY. after the Middle Eocene period. During that period, the sea prevailed where these chains now rise; for Nummulites and their accompanying Testacea were unquestionably inhabitants of salt ; The Ccelenterafes of the Eocene are represented principally by Corals, mostly of types identical with or nearly allied to those now in existence. Perhaps the most characteristic group of these is that of the Turbinolidce, comprising a number of simple " cup-corals," which probably lived in moderately deep water. One of the forms belonging to this family is here figured (fig. 215). Besides true Corals, the Eocene deposits have }delded the remains of the " Sea- pens " {FeimatididcB) and the branched skeletons of the "Sea-shrubs" {GorgonidcE). The EchinodenNs are represented prin- cipally by Sea-urchins, and demand nothing more than mention. It is to be observed, however, that the great group of the Sea- lilies [Crinoids) is now verging on extinc- tion, and is but very feebly represented. Amongst thtMoihisca, Polyzoaiis and Brachiopods also require no special men- tion, beyond the fact that the latter are greatly reduced in numbers, and belong principally to the existing genera Tere- bratula and Rhy7ichonella. The Bivalves {^La7nellibranchs) and the Univalves i^Gas- teropods) are exceedingly numerous, and almost all the priiicipal existing genera are now represented; though less than five per cent of the Eocene species are identical with those now living. It is difficult to make any selection from the many Bivalves which are known in deposits of this age but species of Cai'dita, Crassatella, Leda Cyrena^ Afadra, Cardium, Psa??wwbia,^c. may be mentioned as very characteristic The Cardita planicosta here figured (fig 216) is not only very abundant in the Middle Eocene, bu
Size: 860px × 2905px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentur, bookdecade1870, booksubjectpaleontology, bookyear1876
