. Text-book of zoology for junior students. Zoology. 21G INVEitXEHRATK ANIMALS. known, excejit that it niiiMt cfrtuinly . to UKiintaiii tlie vitality of the shell. Of the fossil Tetridiraui-lniitii the most important are the Ortho- ivi-atd and l\i& Ammonitrx. The Orlhorerotn played a very important part iu the seas of the Paheozoie or Ancient-life ]ierii>d of the earth's history, in which they apparently lilled the ]>taee now taken Ijy the predaceons Cuttle-tishes. They anieed with the NnntHiis m having a many-chambered shell, diviiled by cnrved partitions, perforated by a tub
. Text-book of zoology for junior students. Zoology. 21G INVEitXEHRATK ANIMALS. known, excejit that it niiiMt cfrtuinly . to UKiintaiii tlie vitality of the shell. Of the fossil Tetridiraui-lniitii the most important are the Ortho- ivi-atd and l\i& Ammonitrx. The Orlhorerotn played a very important part iu the seas of the Paheozoie or Ancient-life ]ierii>d of the earth's history, in which they apparently lilled the ]>taee now taken Ijy the predaceons Cuttle-tishes. They anieed with the NnntHiis m having a many-chambered shell, diviiled by cnrved partitions, perforated by a tube or siphuncle. The shell, however, differed from that of the XautUus in not being curved or coiled up, but in l_>eing straight. In other nearly allied forms the shell was bent or even partially coiled up, but never so completely iis in the true Xniitili. Many of the. Fig. ].âTlic Naiililus (Xniilihis ponipilivx). a Jlaiitlc ; (. Its ilnrsal fcild ; (â : ,. E)v; ( 'S ; ,/⢠Fuiiiid. Orthocei-ata were of size, but some of them were colossal, shells having been found of six o)- seven feet in length, and as thick as the body of a The AitiiiKiiiitrx (lig. 15fi), with a. number of allied forms of varied shapes and l> structure, a])jiear t(. have taken the jilace of the Naatilidii\ to a great extent, in the se:is of the Secondary jieriod ; at which time, too, ])iliraneliiate ('eiilialojjods first made their ap- pearance. The tiiie Anjiiionites I'esembled the Xaiitihix in having a many-ch;inil]eieil shell, which was coiled u|i into a. sjiiral, but the jiositioii of tin' siphuncle was different, and tlu! ])artitions or .se))ta Ijctwccn tlic \:irious chambers (jf the shell were wonderfully folded. 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 resemble the original Nicholson,
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1885
