MOOEE ABXOEMAL SECONDARY DEPOSITS. 537 



trict, since many of the Brocastle fossils appear only in the Ammo- 

 nites-Bucldcmdi zone at Southerndown, or in the upper beds at 

 Bridgend, with A. semicostahis and Sauzianiis. The great abundance 

 of Gryplicea incurva, both at Brocastle and at Sonthcrndown, will at 

 least remove these deposits from the so-called " Infralias." 



YII. COXCLTJSION. 



Prom the peculiar character of the deposits of which I have treated, 

 their study has been attended with much labour and difficulty, and 

 has afforded occupation for several years. Mr. Godwin- Austen, in 

 his elaborate theoretical paper on the extension of the Coal-measures 

 under the South-eastern counties, alluded to the probable presence 

 of an old land-area, of which Prome might occupy the central axis. 

 In confirmation of his view, I am enabled to point not only to the 

 axis of elevation in the basaltic dyke of Eastend, beyond Prome, on 

 the .Mendips, but also to produce Mammalia, Reptilia, and terrestrial 

 JMollusca which were the inhabitants of this area within Ehaetic and 

 Liassic times, and from these and other physical reasons to infer that 

 possibly the Mendips have seldom, or perhaps never, been again 

 entirely submerged, or, if so, that it has been during the latter period. 

 It has been shown that the barrier they have thus interposed has 

 to a great extent modified the physical features of the whole line of 

 country, from Prome through a great part of South "Wales, and shut 

 out the Secondary deposits from the Coal-basin, within which uncon- 

 formability very generally prevails, and that the Secondary beds are 

 very insignificant when compared with their equivalent deposits 

 beyond. The mineral veins of the district show most conclusively 

 that the Carboniferous Limestone must for a very long-extended 

 period have been within the influence of the Liassic seas, and that 

 from the latter have been derived most, if not all, of their mineral 

 treasures, whether iron, or lead, or calamine ; and it will have been 

 seen that whenever the edges of the Lias have met the Carboniferous 

 Limestone, or have been deposited within any of its basins, an 

 altered mineralogical character is always present, which beds on the 

 same horizon lose when beyond its influence. The correct succession 

 from the Keuper, through the Ehcetic, to the Liassic beds, and the 

 precise divisions of the latter, have been pointed out, as well as the 

 pala3ontological and lithological break indicated by the Ehajtic White 

 Lias, from which deposit the entire absence of Yertebrata and Cepha- 

 lopoda has been shown, as well as its probable littoral character. 

 In connexion with the Sutton Stone, it will have been seen tliat its 

 peculiar lithology is only local, and that these beds are truly Liassic, 

 Avhilst many of the shells it contains pass into the higher members 

 of the Liassic series. Many points of pala:ontological interest will 

 have been noticed, especially the wonderfully rich fauna of Brocastle, 

 from which, including the corals, I have obtained nearly 200 species. 

 The curious fossiliferous deposit in the Mendip mine has revealed 

 the presence of a Liassic fauna, of a date prior to the deposition of 

 the minerals therein, which is evidently contemporaneous with that 

 of Brocastle and the Ammonites- Biiclclandi beds of Bath. For the 



