Memoirs of the New York State Museum Volume 7

Memoirs of the New York State Museum Volume 7

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904 edition. Excerpt: ...in the figure, are unlike anything known among this family of fossils, and it merits generic distinction." Lapworth refers to it 1887, p.168 as the "dubious genus Staurograptus of Emmons." I have now found in the same region whence Emmons obtained this material, in slates associated with the Upper Cambric Dictyonema flabelliforme bed, a complete series of growth stages pl.2 leading from the sicula through stages identical with if. Emmons's Staurograptus dichotomus TIT to Clonograptus proximatus, a species described by Matthew from the Upper m;;, %.%4m$ggBu,&%;, ) gr; lng.ge, u, ecentss., Cambric of the St John basin. Though the '. mature specimens of the species look very different from the growth stage which Emmons happened to have, the right of priority requires, I think, the recognition of his generic and specific terms. It is evident from Emmons's description that he considered his specimen as full grown, and as having normally "dichotomous cells terminal," but this does not vitiate the fact of his recognizing the diflerential character of this form, consisting in the crucifonn center. The recognition of the generic term Staurograptus would make Hall's term Clonograptus a void synonym, in case the mature form here described should be-referable to the latter genus. It is however certain that the form presents, in its mature stage, characters of Hopkinson's genus Clematograptus 1875, p.652. The latter is characterized in its type species, Cl. im plic at us Hopk., by the radial disposition of its branches, which branch so closely to the sicula that they all appear to spring at once from the center, and that the "funicle " of other Dichograptidae is hardlshow more

Product details

  • Paperback | 102 pages
  • 189 x 246 x 5mm | 195g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236831713
  • 9781236831712