. Report upon the palaeontology of the province of Ontario [microform]. Paleontology; Paléontologie. 7« m I. cardiral an<^les ; dorsal vulvc very moderately concave or nearly flat. The surface ia marked by from twenty to twenty four simple, sub-angular ribs, some of which are occasionally bifur- cated towards the mar^'in, and which are sepnrated by interspaces wider than themselves. In the eared examples the ribs are obsolete towards the cardinal angles. " The cardinal margin shows two and rarely three spines on each side of the centre, which arc abruptly bent outwards so as to lie nea
. Report upon the palaeontology of the province of Ontario [microform]. Paleontology; Paléontologie. 7« m I. cardiral an<^les ; dorsal vulvc very moderately concave or nearly flat. The surface ia marked by from twenty to twenty four simple, sub-angular ribs, some of which are occasionally bifur- cated towards the mar^'in, and which are sepnrated by interspaces wider than themselves. In the eared examples the ribs are obsolete towards the cardinal angles. " The cardinal margin shows two and rarely three spines on each side of the centre, which arc abruptly bent outwards so as to lie nearly parallel to the hinge-line, and the outer one extending much beyond the cardinal extremity. The a:ea is very narrow," (Ilnll), Some of the points mentioned in the above description I have not been able toverify from ourspecimens, as theyare mostly imper feet. Thus, I have never seen either a dorsal valve, or a ventral valve exhibiting the spines. Upon the whole, however, I have no doubt but that our specimens are truly referable to C. mucronufa, as they agree with li all's description of this species in all essential characters, so far as observed. As occurring in the Marccllus Shale, the ventral valve is stated by Hall as being only slightly convex or nearly flat; but as occurring in the Corniferous Lime- siw', aftri- ii;iii; ((. Tiiu huiiic en- stonc and Hamilton group, it is said to be "often quite gibbous. larked; h A tipeoiiiRn uf c. mu- (jy,. examples agree with the latter in this, and only diflFer in hav- en (i«^( from the Coriiiteriius . i- i i i ,1 ^ f ^ 1 Limestone of Ontario. Natural ing tiie cardinal angles more or less produced and salient—a piie- *'''"-'• nomenon, however, wliich Hall states to be of occasional occurrence. The species is nearly allied to C'/iO/iefe dcjlcda (Hall), and the two are, perhaps, only varieties of a single species. Loraiihj and jmiimt'mi.—Rather abundant in the Corniferous Limestone of Kama's Farm, near Port C
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectpaleontology, bookyea
