﻿68 MR. S. S. BUCKMAN ON CERTAIN [Feb. I9IO,. 



possible to say that species known to have existed during the 

 various dates Witcliellice to niortensis hemerae are found in this bed. 



The bed below is another example of the same phenomenon- 

 it is a yellow marly conglomerate of very irregular thickness — 

 generally no more than a couple of inches ; and it is cemented on 

 to a sandstone-bed below, though portions of it are sometimes- 

 found striking to the base of inverted blocks of the snuff-box bed. 



This ' Yellow Conglomerate Bed/ as it may be called, is really no 

 more than a parting between the snuff-box bed and the sandstone- 

 (scissum) bed. But it contains a rich assemblage of mostly small 

 fossils of many different dates. Its latest fossils are of the date of 

 discitce hem era ; and so it may be supposed that the bed was- 

 formed during that date, deriving materials from the destruction of 

 earlier deposits. 



The characteristic fossils of the discitce hemera are carinatitabulate 

 Hildoceratids of the Reynesella, Darellia, etc. pattern x : small 

 gastropoda characteristic of the discitce bed of Bradford Abbas ;. 

 Belemnites of the blainvillei type, and so forth. Indications of 

 concavi hemera are various small Ludwigellce. Fragments of fine- 

 ribbed gradumbilicate Hildoceratids indicate derivation from strata 

 of bradfordensis date ; while such a species as Cirrus nodosum 

 points to strata of murcliisonce, or perhaps earlier, Ancolioceras-- 

 hemera. Then there are derived fragments of the scissum bed 

 included. 



Below the Yellow Conglomerate Bed is the scissum bed — a sand- 

 stone, or sandy limestone, of a bluish-grey colour. This bed yielded 

 the series of Liocerata described in my Monogr. Suppl. pp. xxxvi 

 et seqq. It also furnished Tmetoceras scissum (from which it takes 

 its name) and Tm. circidare, besides yielding species of a rather 

 remarkable series of Hammatoceratidae. For these a new generic 

 name Burtonia is proposed 2 ; and they are remarkable for their 

 likeness to what used to be known in a wide sense as Ammonites 

 murc/iisonce obtusus ; the likeness has not improbably led to con- 

 fusion in regard to zonal identification ; at any rate it would be 

 desirable to be sceptical about any records of A. murchisonce "from 

 Burton or the neighbourhood to the north. 



Below the scissum bed is a brown marly layer, whence has come 

 Zeilleria (or OmitJiella) oppeli. 3 In it, too, are various more or 

 less poorly preserved Opalinoid Ammonites, differing from the 

 Liocerata in having a much larger umbilicus in proportion to their 

 tenuity. They are near to Canavarella sceleta* ; but that species, 

 though its horizon is not exactly known, probably came from the 

 sand-rock immediately below. 



This sand-rock yields poorly preserved Opalinoids, of the WalJceria- 

 subglabra pattern; but the collection of identifiable specimens in 

 situ is difficult. 



1 ' Monogr. Inf. Ool. Aram.' Suppl. (1906-07) pp. cv et seqq. 



2 See the pakeontological paper, p. 97. 



3 Quart. Journ. Geol. Soe. vol. lii (1896) p. 702. 



4 Monogr. Inf. Ool. Amm.' Suppl. (1906-07) p. cxxix & pi. mi, figs. 19-21 . 



