. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. DEVONIAN AND OLD RED PERIOD. I47 "cells," which are generally borne in rows on the branches, and of which each originally contained a minute animal. The Brachiopods still continue to be represented in great force through all the Devonian deposits, though not occurring in the true Old Red Sandstone. Besides such old types as Orthis, Strophomena, Lingula^ Athyris^ and Rhynchonella^ we find some entirely new ones; whilst various types which only
. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. DEVONIAN AND OLD RED PERIOD. I47 "cells," which are generally borne in rows on the branches, and of which each originally contained a minute animal. The Brachiopods still continue to be represented in great force through all the Devonian deposits, though not occurring in the true Old Red Sandstone. Besides such old types as Orthis, Strophomena, Lingula^ Athyris^ and Rhynchonella^ we find some entirely new ones; whilst various types which only commenced their existence in the Upper Silurian, now under- go a great expansion and development. This last is especially the case with the two families of the SpirifeiHdce and the Pro- ductidce. The Spirifers, in particular, are especially character- istic of the Devonian, both in the Old and New Worlds—some of the most typical forms, such as Spirifera mucronata (fig. 96), having the shell " winged," or with the lateral angles prolonged. Fig. 95. — Spirifera sculptilis. Devonian, Ca- Fig. 96.—Spirifera mucrotiata. Devonian, America, nada. (After Billings.) (After Billings.) to such an extent as to have earned for them the popular name of " ; The closely-allied Spirifera disjimda occurs in Britain, France, Spain, Belgium, Germany, Russia, and China. The family of the Prodiididce commenced to exist in the Upper Silurian, in the genus Chonetes; and we shall heieafter find it culminating in the Carboniferous in many forms of the great genus Producta * itself. In the Devonian period, there is an intermediate state of things, the genus Chonetes being continued in new and varied types, and the Carboniferous ProdiidcB being represented by many forms of the allied group Productella. Amongst other well-known De- vonian Brachiopods may be mentioned the two long-lived and persistent types Atrypa reiiadaris (fig. 97) and Strophojiieiia rhomboid
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Keywords: ., bookcentur, bookdecade1870, booksubjectpaleontology, bookyear1876
