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| Keywords: The Quarterly journal of the Geological Society of London (12711477413).jpg of the Shell of the Hippurites Hippurites are bivalve <br> shells which were attached to the sea-bed and usually gregarious <br> Hke Oysters ; often adhering together by their sides or growing one <br> upon the other They are conical when young ; but soon become <br> cylindrical as they lengthen upwards without increasing in diameter <br> Some are straight others curved ; one of the most common H cornu- <br> vaccinnm is shaped like a cow's horn and attains the length of a <br> foot or more <br> On one side there are three longitudinal furrows extending from <br> the base to the summit ; the upper valve is nearly flat and is per- <br> forated by numerous pores ; sometimes there are two eye-like depres- <br> sions as in H bi-oculatus <br> When broken with a hammer the shell is found to consist of two <br> layers ; the outermost is readily detached leaving a core which is <br> furrowed lengthwise The outer layer is compact and dark-coloured ; <br> its solidity is caused by the infiltration of carbonate of lime Spe- <br> cimens however from the Chalk of Angouleme are quite porous and <br> brittle Here the outer shell consists of a succession of corrugated <br> layers ; the wrinkles radiate from the inner margin and subdivide <br> and anastomose repeatedly leaving interstitial pores By the appo- <br> sition of these pores in the successive layers long unequal tubes are <br> formed parallel with the long axis of the shell and opening on its <br> rim <br> The inner layer is white and laminated like the interior of an <br> oyster-shell with spaces between the laminae like those of the <br> Water-Spondylus and which are of frequent occurrence in the Oyster <br> Fig 1 Section of a fragment o/Ostrea cornucopise showing the <br> spaces formed by the lamince in the interior of the shell <br> also The laminae are as thin as writing-paper sometimes vesicular <br> I am indebted to Dr J E Gray of the British Museum for the use of the <br> woodcuts which have been prepared for the Museum Catalogue ' 35614601 110213 51125 Page 41 Text v 11 http //www biodiversitylibrary org/page/35614601 1855 Geological Society of London NameFound Hippurites NameConfirmed Hippurites EOLID 4773611 NameBankID 4195877 NameFound Hippurites cornu Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 11 1855 Geology Periodicals Smithsonian Libraries bhl page 35614601 dc identifier http //biodiversitylibrary org/page/35614601 smithsonian libraries Information field Flickr posted date ISOdate 2014-02-23 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12711477413 2015-08-26 20 54 31 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1855 Photos uploaded from Flickr by FĂŚ using a script | ||||
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