jEOOEE ABNORMAL SECONDAEY DEPOSITS. 467 



On the upper surfaces of the Firestone may be noticed species of 

 Cidaris, fragments of Lima and Fecten, mth casts of My a, Cardinia, 

 Area, Cardium, Modiola minima, and a few fish-scales. The first 

 notice of Ammonites planorhis was in bed jSTo. 101, almost at the base 

 of the Liassic series ; and it is not improbable that it may be detected 

 still lower. 



e. Tlie Ammonites-planorbis and SandrocJc Beds. — Above the 

 " Eirestones " we reach a very thick series of beds which are always 

 separated by intervening marl beds of greater or less thickness, the 

 marls prevaiKng more especially in the upper members. The lower 

 beds of this series at Camel Hill pass under the name of " Sandrock," 

 though they are, like all the others, true limestones. The organic 

 remains, although individually abundant, are still of comparatively 

 few species in this district. In the beds 104 and 106 we find abun- 

 dance of Avicula decussata, and on the same horizon also, at Hatch, 

 a species which has hitherto been supposed to characterize the 

 " "White Lias," and in the latter bed Ostrea arietis (multicostata), so 

 abundant in the Sutton Stone of South Wales. I shall hereafter 

 show that this species passes high up into the beds of theBath district. 

 The marls 129 and 135 are full of Entomostraca (of two new species, 

 Normania mundula, Jones MS., and CytliereUa aspera, Jones MS.), 

 and more rarely Eoraminifera (of the genera Margimdina, CristeU 

 laria, Frondicidaria, and Trochammina). It is important to observe 

 that Ammonites planorhis passes, from the bed previously men- 

 tioned, almost, if not entirely, through the Camel Hill section. I was 

 unable to examine the uppermost beds for it. With it occm% in bed 

 209, Ammonites Johnstoni and A. angidatus. With these are also 

 Lima gigantea, L. Hermanni, and Nautilus intermedins. In bed 

 144 I observed the first Grypluui incur va, which throughout the 

 section is very rare, but is most abundant in No. 201, where it is 

 associated with A. planorhis. Liassic Belemnites have hitherto been 

 found only in the Bucldandi-beds ; and not a trace of this family 

 was seen at Camel. 



I at first expected to find in a section of such thickness nearly 

 all the Liassic series represented; but only its lower members are 

 here exposed. The Bucklandi-beds which succeed are found at 

 Evercreech, Alford, and other places around ; but reference will more 

 especially be made to these in the Bath district. At Alford I 

 found part of an Ichthyosaurus platyodon, which is in the possession 

 of the Rev. J. G. Thring, of Alford House. Taking into consideration 

 the large development of the lower series as seen at Camel, the ab- 

 sence of the higher members, the dip of the beds, and the fact that 

 the upper marls are in some places shown to be upwards of 100 feet 

 in thickness, I am of opinion that the lower Lias in this part of 

 England must have attained a thickness of from 600 to 800 feet. 



/. Beer Crowcomhe and Hatch Sections. — When I described the 

 sections at Beer, in this Journal, vol xvii. p. 485, it was stated 

 that the passage of the RhaBtic beds upwards was not shown, and 

 that the numerous Rhaetic fossils there found were obtained from 

 blocks that had been brought out of a canal tunnel. Within the last 



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