On the Stratigraphical Position of the Corals of the Lias of the Midland and Western Counties of England and of South Wales

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Abstract
The following stratigraphical list of Lias corals must not be regarded as by any means a complete one, even for the district above mentioned, but rather as a record of such species as I have either collected myself, or such as have been collected within my knowledge, and of which I can therefore speak definitely. This will perhaps afford a sufficient reason for the somewhat personal mode of expression made use of throughout the paper. The nomenclature for horizons which I adopt may possibly be regarded as rather antiquated. For instance, instead of speaking of the zones of Ammonites angulatus and A. Bucklandi , the words “ Lima-beds ” are often used. This is done advisedly, and for the following reasons:— Ammonites Bucklandi is a very rare species throughout the midland counties, and it becomes therefore an uncertain guide. And although Ammonites angulatus is abundant enough; its vertical range is so great that, unless assisted by other associate organisms, it becomes practically useless in determining the stratigraphical position of a coral. The greater number of Isastrææ and Septastrææ occur in a rather restricted bed underlying the so-called Lima -beds; and in this Ammonites angulatus occurs abundantly. :But it also appears up through the whole of the Lima-series, though less abundantly, and through the clays containing Ammonites semicostatus and A. Turneri *, and upwards to the top of the zone in which A. planicostatus and Hippopodium ponderosum appear. From this zone I have myself taken it at the north-west end of Welford Hill, four miles west

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