1867.] TATE — A3i:vroxiTES--i>:GiJLAirs zo>sE. 305 



micaceous clays to the '• Bucklandi-beds ;" for at Ballintoy no in- 

 ferior zone is exposed, and at Castle Ciehester no clear downward 

 succession from tlie "Belemnite-beds" can be made out; and I have 

 yet to learn more of the clays at Waterloo, which, from their posi- 

 tion and the dip of the underlying strata, undoubtedly repose on 

 the limestone with Gryphxa incurva. The fossils of these clays are 

 indicative of an horizon on the parallel of, or newer than, that of 

 Ammonites Turneri, which elsewhere is the next higher zone to that 

 of Ammonites Bucldandi. This is to be inferred from the presence 

 of Belemnites alone, ^vhich " are almost never absent from the sec- 

 tion till we reach the zone of Ammonites Buddandi. Only in the 

 upper part of this zone have they been found" *. 



Though Belemnites acutus and B. penicillatus characterize in Eng- 

 land the zones of Ammonites Turneri and A. ohtusus, jet, from the 

 fact of their association in Ireland with Hijypojjodium ^onderosum 

 and Ammonites armatus, belonging to the zone of A. raricostatus, 

 and with other species ranging throughout the upper part of the 

 Lower Lias, I cannot regard the clays conaining them as belonging to 

 any one of the zones of the Lower Lias sujDeiior to the " Bucklandi- 

 beds." 



3. On the FossiLrFEEors Develop^iext of the Zoxe of Ammonites 

 cmgulatus, Schloth., in Gkeat Beitaix. By Ealph Tate, Esq., 

 A.L.S., F.G.S. 



Coxiexts. 



I. Introduction. ' lY. Liassic beds inferior to the Lime- 



II. Occurrences of the Zone of -4//z;/eo- stones of the Ammonites-BucJc- 



nites angulatus. lancli Zone in the Bristol Dis- 



1. Ireland. trict. 



2. Marton, Lincolnshu'e. Y. The Zone of Ammonites angidatus 



3. Warwickshhe. in Dorsetshire. 



4. ]!*s'orth Grloucestershire. YI. Table of British Fossils from the 



5. Brocastle, Glamorganshire. Zone oi Ammonites angidatus. 



III. The Sutton Stone. ' YII. Descriptions of new species. 



I. IxTEonrcTiox. 



The beds comprised between the Avicula-coiitorta series and the 

 limestones of the zone of Ammonites Bucldandi vel hisulcatus 

 have been divided into two lithoiogical horizons, the lower of which, 

 that of Ammonites planorhis, presents no marked zoological facies 

 when contrasted \d\h the upper, that of A. angidatus, which has 

 a fauna exceeding in richness of species the remainder of the Lower 

 Lias. The term " Infra-Kas " has been given to this group of beds ; 

 but as its applicability varies with the classificatory views of indi- 

 vidual authors, it seems, therefore, inadmissible ; and, in my opinion, 

 that of ''* Hettangian," as suggested by Prof. Eenevierf, should be 

 used instead. 



The classification of the members of the Lias would then stand 

 thus : — 



* Philhps, " Liassic Belemnites," Mon. Pal. Soc. for 1864, p. 32 : 1866. 

 t L'iiifralias des Alpes Yaudoises, Bull. Soc. Geol. de Fr. vol. xzi., 1864. 



