. The geology of Nova Scotia, New Brunswick, and Prince Edward Island, or, Acadian geology [microform]. Geology; Geology, Stratigraphic; Paleontology; Geology, Economic; Géologie; Géologie stratigraphique; Paléontologie; Géologie économique. â J 096 THE UPPER SILUltUN. ventral valve variably convex, and often showing a flattened or alightly concave space down the middle of the shell; cardinal margin ornamented by four or five minute spines on each side of the beak; cardino-lateral margins often a little wrinkled; surface finely striated, BtrisB flexuouH, dichotomising and increasing by in
. The geology of Nova Scotia, New Brunswick, and Prince Edward Island, or, Acadian geology [microform]. Geology; Geology, Stratigraphic; Paleontology; Geology, Economic; Géologie; Géologie stratigraphique; Paléontologie; Géologie économique. â J 096 THE UPPER SILUltUN. ventral valve variably convex, and often showing a flattened or alightly concave space down the middle of the shell; cardinal margin ornamented by four or five minute spines on each side of the beak; cardino-lateral margins often a little wrinkled; surface finely striated, BtrisB flexuouH, dichotomising and increasing by interstitial addition, BO that tiiere are more tlian 100 on the margin of the shell; striw increasing in size below the umbo; concentric strito fine, close, rounded and slightly undulating. Fig. 198. Crania Acaiiiensit. Fig. 199. ChoneUt Nova Scotica, and portions magnijied. Fig. 200. C'honttea tenuiatruila. Pig. 20'.. Trematospirn Acadia. ^. Fig. 202. Leplocotlia intermedia. Dorsal valve moderately concave; strite much stronger below the middle of the shell and sometimes bifurcating toward tlio margin. This species resembles in form the Chonetes cornuta of the Clinton group of New York, but is a much larger and more ventricose shell; the striae are proportionally less numerous and more closely arranged, the interstices being less than the striae, while in the C. cornuta the interstices are wider than the striaj, and the latter increase only by interstitial additions below the middle of the shell. A stronger and more elevated stria often marks the median line from beak to base of the ventral valve. Arisaig, East River, Nictaux, coll. J. W. D. Phonetes tenuistriata, Hall (Fig. 200). Shell semi-oval, twice as wide as long; ventral valve moderately convex, hinge-line equalling the width of the shell; surface marked by fine, even, closely arranged striae, which apparently increase only by interstitial additions, and arc not flexuous. The number of striae on the margin of t
Size: 2583px × 968px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectgeology, booksubjectpaleontology
