. On some fossils from the primordial rocks of Newfoundland [microform]. Paleontology; Paléontologie. No. 4.] BILLINOS—FOSSILS OF NE^.TOUI^DLAND. 469 The shell which, is supposed to be the ventral valve of thi« species, is gently convex, with usually a somewhat flat space extending from the front margin upwards towards the beak. The apical angle appears to bo from 00 to 100 degrees. Shell very thick, of a lamellar structure, dark brown or nearly black, and, sometimes, whore exfoliated, of an ashy grey colour. Sur- face with a number of obscure undulations of growth and with fine longitudinal s
. On some fossils from the primordial rocks of Newfoundland [microform]. Paleontology; Paléontologie. No. 4.] BILLINOS—FOSSILS OF NE^.TOUI^DLAND. 469 The shell which, is supposed to be the ventral valve of thi« species, is gently convex, with usually a somewhat flat space extending from the front margin upwards towards the beak. The apical angle appears to bo from 00 to 100 degrees. Shell very thick, of a lamellar structure, dark brown or nearly black, and, sometimes, whore exfoliated, of an ashy grey colour. Sur- face with a number of obscure undulations of growth and with fine longitudinal strijc, about ten in the width of one line. * Cruziana similis, spec. I Fir. f). Cruziami Kunilix ; 7, tlie median pjronvc : r, r, the ridges at iho sides. The specimens arc from twelve to fifteen lines wide, divided along the middle by an angular groove, and bordered on each side by a narrow ridge, about one line wide. The spa(!0 on each side between the median groove and the marginal ridges, are moderately convex and obli([uely by numerous irregular raised lines, with furrows between them. These lines usually have the form of a gentle sigmoid curve, sometimes extending (juite across, but are often ««—^ -d together in a somewhat con- fused manncT, still preserving ihe gentiral oblique direction. Upon an average there are about ten lines in the 1 mgth of half an inch. The marginal ridges arc sometimes longitudinally striated. This species has been heretofore referred by me to C. semi- pUcata, Salter, but although closely allied, none of our specimens agree exactly with the figures of the British species. Besides the above six species, many of the beds of sandstone of Great Boll Island, arc covered with several species of Pal(eo- V C;- .>CL fU /. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the origin
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Keywords: ., bookcentury1800, bookdecade1870, bookpub, booksubjectpaleontology
