. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. THE CAMBRIAN PERIOD. 85 in some of the Cambrian Trilobites, such as the little Agnosti (fig. 31 g)^ the animal was blind. The lateral portions of the. Fig. 31.—Cambrian Trilobites: a, Paradoxides Bokemicus, reduced in size; b, Ellip- socephaltis Hoffi ; c, Sao hirsjita ; d, Conocorypke Sultzeri {zSS. the above, together with fig. ;f, are from the Upper Cambrian or "Primordial Zone " of Bohemia); e. Head-shield QiiDikellocephalus Celticus, fro
. The ancient life-history of the earth; a comprehensive outline of the principles and leading facts of palaeontological science. Paleontology. THE CAMBRIAN PERIOD. 85 in some of the Cambrian Trilobites, such as the little Agnosti (fig. 31 g)^ the animal was blind. The lateral portions of the. Fig. 31.—Cambrian Trilobites: a, Paradoxides Bokemicus, reduced in size; b, Ellip- socephaltis Hoffi ; c, Sao hirsjita ; d, Conocorypke Sultzeri {zSS. the above, together with fig. ;f, are from the Upper Cambrian or "Primordial Zone " of Bohemia); e. Head-shield QiiDikellocephalus Celticus, from the Lingula Flags of Wales; f, Head-shield o{Cono- corypfie Matthewi, from the Upper Cambrian (Acadian Group) of New Brunswick; g, Agnosttis rex, Bohemia ; h, Tail-shield o^Dikellocephalus Minnesotensis, from the Upper Cambrian (Potsdam Sandstone) of Minnesota. (After Barrande, Dawson, Salter, and Dale Owen.) head-shield are usually separated from the central portion by a pecuHar line of division (the so-called " facial suture ") on each side; but this is also wanting in some of the Cambrian species. The backward angles of the head-shield, also, are often prolonged into spines, which sometimes reach a great length. Following the head-shield behind, we have a portion of the body which is composed of movable segments or "body- rings," and which is technically called the " ; Ordi- narily, this region is strongly trilobed, and each ring consists of a central convex portion, and of two flatter side-lobes. The number of body-rings in the thorax is very variable (from two to twenty-six), but is fixed for the adult forms of each group of the Trilobites. The young forms have much fewer rings than the full-grown ones ; and it is curious to find that the Cam-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly
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Keywords: ., bookcentur, bookdecade1870, booksubjectpaleontology, bookyear1876
