1868.] STODDART LOWER LIAS OF BRISTOL. 201 



1. Aramonites-semicostatus Bed. — There is here only 1 foot of dark 

 shale between two tliin bods of limestone, containing many crushed 

 specimens of A. semicostutus (Y. and B.), mixed with a few joints 

 of Pentacrini. 



A little further on, these beds yield A. Saiizeanus, Acrodus no- 

 hilis, &c. in abundance. 



2. Saurian Bed. — This bed contains a great number of the ver- 

 tebrae and bones of Ichthyosaurus and Plesiosaurus, with occasionally 

 a Nautilus. 



3. Conyheari-hed. — A bed of hard limestone, lying immediately 

 below No. 2. On its upper surface specimens of A. Bucklandi 

 and A. Conyheari lie in great numbers. 



I consider this to be the beginning of the A.-BucHandi zone. 

 Underneath this bed, NaiUili occur in good condition. 



4. Lima-beds. — These are a series of very blue argillaceous lime- 

 stone beds, divided by dark shales. Their average composition is 

 90 per cent, carbonate of lime, 6 of sulphate of lime, and 4 of silica, 

 alumina, and oxide of iron. 



The upper twelve beds contain immense quantities of Gryphoia 

 incurva, sometimes in nests of 40 or 50 valves. Plicatula intusstriataj 

 Emmerich, is also abundant. I have a specimen of Gryphcea with 

 five Plicatulce upon it. The Plicatula intusstriata exactly cor- 

 responds with Moore's figure, pi. 16. fig. 25, both in size and 

 markings. 



With them occur plentifully Ammonites angulatus, Schloth., or at 

 least portions ; for a perfect shell is hardly ever found. 



Prom these beds also are collected PUurofomaria Ayiglica, Phola- 

 domya glabra, Lima pectinoides, Pecten textorius, Wiynchonella va- 

 riabilis, and some small species of Chemnitzia. 



The succeeding beds are covered up for a short distance, and then 

 we come to 



5. Ammonites-torus Bed. — About four feet below the surface of this 

 quarry occurs a bed of limestone, containing A. torus and A. tortilis 

 of D'Orbigny. 



With them are also scales of Pholidophorus nitidus. They are, 

 however, more plentiful in a ferruginous bed just below, associated 

 with those of Gyrolepis Alberti. 



6. Echinoderm-beds. — These, the most interesting beds of the 

 whole quarry, are full of the spines and jaws of Cidaris Edwardsi, 

 and spines of Hemipedina Bechei. The little jaws are very abundant. 

 They are preserved in most perfect condition, showing the striated 

 side and crenated edge, like those of the recent Echinus miliaris. 



With them are multitudes of beautiful little Cytheridce, a few 

 Foraminifera, small teeth, and shell-debris. 



All these are to be collected in any quantitiy ; and as these beds 

 extend for miles, the profusion of Echinoderms must have been 

 astonishingly great when these strata were deposited. 



7. Johnstoni-beds. — There are 29 beds, chiefly consisting of 

 fissile, slaty, very argillaceous sandstones and limestones. The 

 specimens of Ammonites Johnstoni are very abundant and large. 



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