A guide to the fossil invertebrate animals in the Department of geology and palaeontology in the British museum (Natural history) . Fig. 93.—Goniatites. a, Pronorites cyclolobiis, and 6, Glyphioceras sphae-ricum, Carboniferous Limestone, England, c, Agathiceras Suessi, with shell preserved, Permo-Carboniferous, Sicily.(From Foord and Crick.) Natural size. and its globular shape is apparent. In others the shell soonbecame more tightly coiled (Fig. 93 h), till the protoconch ishidden by subsequent whorls (Fig. 93 c). As the shell MOLLUSCA—CEPHALOPODA. 165 became coiled, its septa were thrown int
A guide to the fossil invertebrate animals in the Department of geology and palaeontology in the British museum (Natural history) . Fig. 93.—Goniatites. a, Pronorites cyclolobiis, and 6, Glyphioceras sphae-ricum, Carboniferous Limestone, England, c, Agathiceras Suessi, with shell preserved, Permo-Carboniferous, Sicily.(From Foord and Crick.) Natural size. and its globular shape is apparent. In others the shell soonbecame more tightly coiled (Fig. 93 h), till the protoconch ishidden by subsequent whorls (Fig. 93 c). As the shell MOLLUSCA—CEPHALOPODA. 165 became coiled, its septa were thrown into folds, but these Gallery-were generally of a relatively simple character with anangular suture (Fig. 93 h), whence these forms are collectively Iable-casknown as Goniatites. They are usually smooth, or withonly fine lines of growth, rarely with tubercles or ribs. Thegoniatites are mostly of Devonian and Carboniferous age,but also occur in the Permian, after which they give place tothe Ammonites. Among the genera here exhibited may benoticed the above-mentioned Mimoceras, and Agoniatitesfecundus also showing the uncoiled
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Keywords: ., bookauthorbr, bookcentury1900, bookdecade1900, booksubjectfossils
