A guide to the fossil invertebrate animals in the Department of geology and palaeontology in the British museum (Natural history) ... / With 7 plates and 96 textfigures.

British Museum (Natural History). Department of Geology

Date:: 1911

Credit: A guide to the fossil invertebrate animals in the Department of geology and palaeontology in the British museum (Natural history) ... / With 7 plates and 96 textfigures. Source: Wellcome Collection.

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$Gallery their ormxment. Adjoining these are .shells from the Kella- ways Eock, a brownish sandstone at the base of the Oxford Clay, giving a name to the Callovian Age. Among these are Gnjphaea hilohata with a curious fold on its side, Isocardia minima, and Goniomya Y-scri2)ta. The shells of Bathonian age are arranged under the formations from which they come. First are those from the Table-ease widely distributed rubbly limestone called Cornbrash, which has yielded the scaphopod Dcntalucm annulaium, the gastropods Bulla undulata, Pseudomdania vittata, and the lamellibranchs Ghlamys \Pectcn\ vagans, Lima dxtplicata, • Pscudomonolis \_Avicnht\ ediinata, and several Trigonias. IVIany of the specimens are figured in Blake’s “ Monograph of Cornbrash Fossils.” There are very few shells from the Forest Marble, but among them is a fine examjile of Trigonia detrita figured by Lycett. In the equally small series from the Bradford Clay, one may notice a set of Table-cases Oxytoma \Amcula\ costata. The Great Oolite shells are ^ mostly from the Oolitic freestone. Here is the type-specimen of Fteroccra Wrighti, a fine winged shell; then several species of Purpuroidca, among which P. morrisea with its heavy spines is conspicuous ; several limpets, Patella, testify to the rocky nature of the sea-floor; Ncrita rugosa seems to show bands of colour, and such are still more evident in a large form of Natica. Among lamellibranchs one may note TAma cardiiformis, Ptcroperna costatula. Pinna amjda, Paralldodon [Macrodon'] hirsonensis, and the massive Padiy- risma (“thick support”) grande. The Stonesfield Slate yields Trigonia impressa and Pinna cxineata. The small series from the Fuller’s Earth includes Volsella [Jilodiola'] imhricata and Ceromya plicata. Table-cases Next come shells from the variable series of marine 12 & 13. limestones known as the Inferior Oolite, deposited mainly in Bajocian time. The chief localities in the south-west of England here represented are Dundry near Bristol, Half- way House near Yeovil, Bradford Abbas, and Leckhampton Hill near Cheltenham. These have yielded a fine series of Pleurotomaria, many species of Amberleya, Pseudomdania, Ptirpurina, Ddp>liinula, Ccriihium, Ciri'us, Nerinaea, Alaria, and otlier gastropods. Certain species of Amberleya, Ceri- tliium, Onustus, and Neridonms acquired an interest a few years ago from their resemblance to some shells now living in Lake Tanganyika; but it is not now imagined that the animals themselves had the same structure. Similar$