Spondylus hilli Cragin, 1893
CRAGIN, F. W. 1893. A Contribution to the Invertebrate Paleontology of the Texas Cretaceous. Geological Survey of Texas, Annual Report, 4: 139-292, pls. 24-45. [p. 211, pl. 33, figs. 1-3]
1893 Spondylus hilli Cragin, 1893
F. W. Cragin, plate 33.
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«Shell somewhat larger, less compressed, and more broadly ovate than S. guadalupae, Roemer, and the beak of the left valve more elevated and produced and strongly incurved; both valves ornamented with rather fine but somewhat unequal radiating raised lines, each of which is rather sharply elevated, but unevenly so along its course, ribs not prominent, those of the left valve furnished rather sparingly and irregularly with small granule-like to erect point-like spines, those of the right valve armed more abundantly with erect, transversely flattened, round-ended to truncate spines which are more or less concave on the side that looks toward the basal margin and of a much broader and shorter type than those represented in S. guadalupae by Dr. Roemer (Kreideb. , Taf. VIII, fig. 9), the anterior spines being relatively narrow, those of the mid-region having variously the breadth greater than the height or vice versa, and those of the posterior part being connate from rib to rib and thus forming high and very broad flange-like plates which project far beyond the posterior margin of the shell; spines of adjacent ribs occasionally connate on other parts of the valve.
Measurements.— Height of right valve 54, of left valve 46, of hinge-margin above base 43, length 43, same to outer extremity of the posterior lamelloid spines 47, breadth from convexity of left valve to opposite point of the right 30 mm. Occurrence.— The type of the species is a beautifully preserved specimen from the Fort Worth limestone. It was collected by Mr. Leverett, about a mile and a half east of Georgetown, on the San Gabriel river. The Spondylus hilli is apparently analogous with the Neocomian S. roemeri, Desh. Some four years ago, Prof. Hill noted the occurrence, in the Fort Worth limestone, of a Spondylus of "a larger and different species from any hitherto noted in Texas" (Bul. Geol. Surv. Tex., No. 4, p. 7), listing as previously noted in the State only S. guadalupae of the Austin limestone. The chances are that the species here described is the same as that observed by him in the Fort Worth, and I take pleasure in naming it after him.» FRANCIS WHITTEMORE CRAGIN, 1893
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