We have hitherto confined our attention to the Cephalopods; but the Gasteropods tell the same tale. In the Bradford-Abbas quarry alone have been found as many as fifty species of univalves, many of which belong to the Cotteswolds[1]. There is, however, a large array of new forms in the genera Pleurotomaria, Chemnitzia, Turbo, Trochus, Natica and Solarium; and others abound.
These, like the Ammonites, are in a wonderful state of preservation.
The Brachiopoda are not so numerous as in the Cotteswold district; still the forms met with in the Cephalopoda-bed point also to the high position it occupies in the Inferior Oolite; such are
|
Terebratula Phillipsii, Mor. & Dav. |
Terebratula sphæroidalis, Sow. |
And others abound.
The Conchifera afford a list for our limited area as large as is to be met with in the whole of the Cotteswolds, numbering over 150 species. Amongst them the following genera—Trigonia, Lima, Pecten, Cucullæa, Modiola, Perna, Cardium, Astarte, and others, present a most interesting assemblage of forms.
Neither the Echinodermata nor the Zoophyta present the same number of species as the Cotteswolds; but in places a few species occur abundantly.
Taken then as a whole, we may conclude that the Dorset Cephalopoda-bed is one of the richest deposits in the country, although as yet we cannot pretend to have exhausted or to have made out all its treasures; but it would seem that within this thin stratum are stored up most of the important forms which make up the mass of the Cotteswold fauna.
It would appear, indeed, that out of about 250 species of shells tabulated by myself in the second edition of Murchison's 'Geology of Cheltenham,' fully 200 belong to the Cephalopoda-bed of Dorset; whilst in this latter county are found many specimens of which the Cotteswolds cannot boast, most of which, so far as the Cephalopoda and Gasteropoda are concerned, are figured in D'Orbigny's 'Terrains Jurassiques.'
