. Geological magazine. thus exhibiting an impression of the extremelyfine and close longitudinal striee which adorn the internal surface ofthe valve, and which extend to within a short distance of the margin. This shell is named in honour of Dr. W. T. Blanford, CLE.,, a former Director of the Geological Survey of India, and oneof the earliest writers on the geology of the Mekran Coast. Examples.—Only three or four specimens in the collection. Mactra mekranensis, (PI. XVI, Figs. 6, 7.)Shell subtriangularly ovate, cordiform, moderately convex, obtusely angulate posteriorly ; umbones
. Geological magazine. thus exhibiting an impression of the extremelyfine and close longitudinal striee which adorn the internal surface ofthe valve, and which extend to within a short distance of the margin. This shell is named in honour of Dr. W. T. Blanford, CLE.,, a former Director of the Geological Survey of India, and oneof the earliest writers on the geology of the Mekran Coast. Examples.—Only three or four specimens in the collection. Mactra mekranensis, (PI. XVI, Figs. 6, 7.)Shell subtriangularly ovate, cordiform, moderately convex, obtusely angulate posteriorly ; umbones nearly central; sculpture consisting. of narrow, depressed, smooth, concentric banding of equal width, each band separated by an extremely narrow sulcation. Dimensions.—Eight valve : umbono-ventral, 40; antero-posterior, 47; diameter, 10 mm. The specimen referred to this form is represented by a right valve, being mainly an internal cast, yet retaining a small patch of original Tertiary Shells in nodulesfrom tlie Mekran Coast. imp. irgest. Smallest. 48 ., 35 mm. 48 ., ,. 35 „ 38 ., .. 28 „ R. Bullen Newton—Marine Fossils from Mekrcin Coast. 299 shell structure on the postero-ventral region, which well illustratesthe smooth, narrow-banded character of the sculpture. I have netbeen successful in discovering a shell which is suitable for com-parison with this species, either among modern or fossil forms, itschief characters having reference to the triangularly oval shape andthe regular concentric banding which ornaments the —One specimen only in the collection. Cakdium Melvilli, (PI. XVI, Figs. 1-4.)Shell globose, nearly equilateral, radiately costated; costee about37, depressed, angulated at the sides, separated by narrow, deepinterspaces about one-half the width of the ribs (as seen near theventral margin); umbones rounded, incurved, subcentral. Dimensions.—Umbono-ventr
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1864
