Hardwicke's science-gossip : an illustrated medium of interchange and gossip for students and lovers of nature . Fig. 99.—Pafeto-quadrato-mandibiilar arch (= jaws)of Spinax (nat. size), s, suspensorium. Fig. 100.—Outline of Spinax (much reduced).—a, spiracle ; li^ V^, dorsalfin-spines; c, giIl-openings|; d, mouth; e, nostrils;y, eye. methods of grouping living animals must generallydiffer greatly from those employed in the case of theextinct forms, and consequently it is obvious thatpalseontological species are nearly always distinct inkind from zoological species. This ischiefly
Hardwicke's science-gossip : an illustrated medium of interchange and gossip for students and lovers of nature . Fig. 99.—Pafeto-quadrato-mandibiilar arch (= jaws)of Spinax (nat. size), s, suspensorium. Fig. 100.—Outline of Spinax (much reduced).—a, spiracle ; li^ V^, dorsalfin-spines; c, giIl-openings|; d, mouth; e, nostrils;y, eye. methods of grouping living animals must generallydiffer greatly from those employed in the case of theextinct forms, and consequently it is obvious thatpalseontological species are nearly always distinct inkind from zoological species. This ischiefly brougiit about, as is well known, through thefragmentary nature of most fossilised organic remains ;and the imperfection in materials is due to the fact,that only the hard parts of animals have usually beenpreserved, while the softer tissues—so important forclassificatory purposes—have almost always beencompletely destroyed. Now, of all the groups of fossils, there is, perhaps,none which exhibits more clearly the difficulties of apalseontologist than that comprising the elcs ofsharks and rays. Th
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Keywords: ., bookcentury1800, booksubjectnaturalhistory, booksubjectscience
