. Acadian geology [microform] : the geological structure, organic remains and mineral resources of Nova Scotia, New Brunswick and Prince Edward Island. Geology; Paleontology; Geology; Geology; Geologie; Paléontologie; Géologie; Géologie. if: || \ :. ! ' 1 1 . i â ' 1 !:' â 1 ! i i J 11 ! i â â i 1:. I «l Ijjl; i 294 THE CARBONIFEROUS SYSTEil. that Phillips himself figures a ripccimeu of his Tcrebratula rhomhoidea with a simple mesial fold, wc need not he surprised to find the same peculiarity in one of those from Nova Scotia. Indeed, after carefully examining the three examples forwarded b
. Acadian geology [microform] : the geological structure, organic remains and mineral resources of Nova Scotia, New Brunswick and Prince Edward Island. Geology; Paleontology; Geology; Geology; Geologie; Paléontologie; Géologie; Géologie. if: || \ :. ! ' 1 1 . i â ' 1 !:' â 1 ! i i J 11 ! i â â i 1:. I «l Ijjl; i 294 THE CARBONIFEROUS SYSTEil. that Phillips himself figures a ripccimeu of his Tcrebratula rhomhoidea with a simple mesial fold, wc need not he surprised to find the same peculiarity in one of those from Nova Scotia. Indeed, after carefully examining the three examples forwarded by Dr Dawson, I cannot bring myself to believe that they should be sj)ecifically separated. It is well known that the sainc peculiarity occurs with Rhynchonella acuminata; and any one who examines ])latcs 20 and 21 of my 'Mono- grajih of Biitish Carboniferous, Brachiopoda' must feel surprised at the immense variability of which some species are susceptible. Fig. 93.âRhjnclwnella Dawsoniana, Davidson ; nat. size and 'â 'â Rhynchonella Daivsoniana, n. sp. (Fig. 93,ff,5). "Shell very small, almost circular, a little wider than long; dorsal valve moderately and uniformly convex to about half its length from the umbone, at which point a very slightly elevated and flattened mesial fold begins to rise, and extends to the front; the surface of the shell is also either almost entirely smooth or ornamented with from eight to twelve slightly marked ribs. The ventral valve is gently convex, with a wide sinus; beak small and incurved. Length three and a half lines, width four lines, deptli two and a half lines. " This small species does not appear to be rare in a black Lower Carboniferous limestone at Lennox Passage, and is not unlike, except in size, certain examples of M. do Verncuil's Tcrebratula superstes ; but this last-named Permian shell belongs to the genus Camarophoria, while the one under description belongs to Rhjnchonella. I have compared it w
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Keywords: ., boo, bookcentury1800, booksubjectgeology, booksubjectpaleontology
