12 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 6, 



Pygaster conoideus, Wr. 

 Byboclypus agariciformis, Forb. 

 Goniaster ; fragment of a ray. 

 Pentaerinus ; 2 sp. 



Thamnastraea fungiformis, E. Sf H. 



Stromatopora dichotomoides, d' Orb. 

 Diastoporp -Waltonii, Haime. 

 ? ^^jA^i, de Blainv. 



Montlivaltia Delabechei, Edw. 8{ Haime. f &■ ^^ ^,'o^h Haime. 



Waterhousei, E. $ H. \ ^ < c . \ . > Haime. 



cupuliformis, E. $ H. V ^TTo^ . . +iminea, Phil. 



Axosraiiia Wrightii, E. $ H. Lichenopora Puiillipsii, Haime. 



Latomseandraea Flemingii, E. §■ H. 

 Isastraea tenuistriata, E. 8[ H. 



limitata, E $ H. 



Thamnastraea Mettensis, E. $ H. 

 Defranciana, E. Sf H. 



iN'e.tecpora dayjaicornis, Lamour. 

 Heterorjora co nifera, Lamour. 



puitulosa't, Michel. 



TheonoaBow^rbankii, Haime. 

 Berenicea duuviana, Lamour. 



b. The Oolite-Marl or Fimbria-bed. — This remarkable bed is a well- 

 marked feature in the Leckhampton Hill section, and forms the 

 uppermost portion of the zone of Ammonites Murchisonce. It is a 

 very persistent stratum in the northern and middle Cotteswolds, 

 and extends across this portion of the plateau from the vales of 

 Moreton and Bourton, on the east, to the mural escarpments of the 

 oolites on the west ; but it appears to be absent from the southern 

 part of the range. 



The oolite-marl resembles indurated chalk, and, being inter- 

 stratified between two beds of oolitic limestone, forms a conspicuous 

 feature in the sections where it is so exposed. It rests upon the 

 uppermost bed of the building-freestone, and underlies a thin- 

 bedded oolitic limestone. The marl varies from two to eight feet in 

 thickness, and, when exposed to atmospheric agency, breaks up into 

 cuboidal masses. 



This rock appears to have been formed under different conditions 

 to those under which the underlying freestones were deposited : for 

 in some localities it contains masses of coral, chiefly of the genera 

 Thamnastraea and Isastrcea ; in others it is charged with immense 

 numbers of Brachiopoda, especially Terebratula fimbria, T. carinata, 

 T. submaxillata, and others. In some places it abounds with the 

 long slender shells of Nerinaza, forming in one or two localities a 

 " Nerinsean limestone." These paleeontological facts lead to the 

 conclusion that this local stratum owes its origin to a corallige- 

 nous bank in the oolitic sea. Corals are met with in moderate 

 numbers at Leckhampton near Cheltenham, and at Sheepscombe, 

 and Swift's Hill near Stroud : also in several other places Tham- 

 nastrcea and Isastrcea abound ; whilst in the Cheltenham district 

 the marl contains immense numbers of Terebratula fimbria, T. 

 submaxillata, T. carinata, and Rhynchonella Lycetti. At Selsey 

 and Rodborough Hills the marl is represented by a single bed of 

 buff-coloured argillaceous limestone, which contains few fossils and 

 is overlain by a thin-bedded freestone. At Scar Hill near Nails- 

 worth, the representative of the marl contains neither Corals nor 

 Brachiopods, but is charged with long spiral univalves belonging to 

 the genera Chemnitzia and Nerincea, with a few Conchifera and 

 small Gasteropoda. The Nerinaean limestone is a fine argillaceous 

 rock, close in texture, and feebly oolitic, about one foot in thick- 



