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I.—Contributions to the Palæontology of the Yorkshire Oolites

Published online by Cambridge University Press:  01 May 2009

Extract

As in the case of Nerinœa, so also in this genus, we are dealing with its earliest representatives in so far as this district is concerned, since Tate and Blake make no mention of the occurrence of Alaria in the Yorkshire Lias. Piette, who accepts with modification Morris and Lycett's genus for this section of the winged shells, is of opinion that no truly winged shell has ever been found in the Lower Lias of France, though he describes species from the Middle and Upper Lias, none of which, according to his views, pass upwards. It was in the Lower Oolites that the genus Alaria first began to flourish, and we find in most places that it became tolerably well represented as low down as the Inferior Oolite or Bajocian subdivision.

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Copyright
Copyright © Cambridge University Press 1884

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References

page 146 note 1 Geol. Mag. 1880, p. 532.

page 147 note 1 On examining the collection of Sowerby's types at the British Museum, in company with Mr. Etheridge, and Mr. Newton, , we found that, besides the two figured forms, there were several other specimens fixed to the card. One of these comes from the Dogger of the Peak, and is almost identical with the form in the accompanying Plate (VI. Fig. 5). Two others are from the Millepore Rock, or from the ferruginous bed of the Scarborough Limestone, and are good examples of Al. hamus, var. Phillipsii. Of the figured types themselves, the one from Weymouth has been preserved in a hard concretionary ironstone strongly reddened, which probably came from the base of the Oxford Clay, here devoid of any specialized Kellaways Rock. The other, from the roof of the Brora coal, is likewise on the same horizon. Hence, Rostellaria composita, Sow., is to be regarded as a Callovian form, very similar to, if not identical with, Rostellaria seminuda, H. and D., from the Callovian of Montreuil Bellay.Google Scholar

page 148 note 1 In the following measurements of Alaria “length” means the full length of the shell restored, without the canal. In other respects no great accuracy is claimed, since all the specimens are more or less mutilated, and for the most part enveloped in matrix.

page 151 note 1 In describing a specimen from the L. C. G. it was suggested that it might have a two-fingered wing. This I now believe to be a mistake. The chief characteristic of the bispinusa group is the one lateral digitation, which together with the canal sheath or tail constitute two long processes almost at right angles to each other.

page 154 note 1 The specimens thus marked occur on the same block of stone.