292 



J. P. BLAKE AND W. H. HUDLESTOtf ON" 



Yig. 4. — Section of Coral-beds, Hillmarton. 



a. Coral and altered Limestone. 



b. Clay. 



most probable that they are all organic growths on the spot, rather 

 than transported matter. How far they were coralline would be 

 difficult to say. The clays contain some Poraminifera of very 

 unusual character and other Microzoa ; and the limestones are very 

 fossiliferous ; so that at the time of the formation of the beds this 

 spot was teeming with life, among which the Echinodermata were 

 abundantly represented, and the stony Alga3 appear not to have been 

 wanting. Our list from these quarries, to which the fossils collected 

 and recorded by the Survey as from Hillmarton may probably be 

 added, is : — 



Littorina muricata (Sow.). 

 Chemnitzia heddmgtonensis (Sow.). 

 Alaria, sp. (cf. tenuistria, Bnv.). 

 Lithodomus inclusus (Ph.). 

 Pholadomya decemcostata (Rom.). 

 Lucina aliena (Ph.). 

 Astarte ovata (Sow.). 



subdepressa (Bl. <$f H.). 



Cypricardia glabra (Bl. fy H.). 

 Mytilus ungulatus (Y. $ B.). 

 Perna mytiloides (Leon.). 

 Lima elliptica (Whit.). 



pectinif oralis (Sow.). 



densepunctata (Bom.). 



Plicatula, sp. 



Hinnites velatus (Gold/.). 



Pecten qualicosta (Et.). 



vimineus (Sow.). 



Exogyra bruntrutana (Th.). 

 Ostrea gregaria (Sow.). 

 Terebratula insignis (Schl.). 



margarita (Opp.). 



Thecidea ornata (Moore). 

 Cidaris florigerama (Ph.). 



Smithii (Wr.). 



Pseudodiadema versipora (Ph.). 

 Parendea bullata (Et.). 

 Corallina, sp. 



rigida (Sow.). 



Most of these are the true characteristic species of the "C.-flori- 

 gemma Eag " where best developed. 



Rocks of the same epoch, but more closely coinciding in character 

 with the freestones at Calne, occur not far from here, at Goatacre, 

 whence a considerable portion of the building- stone of the neigh- 

 bourhood is obtained. It is here more highly false-bedded, dipping 

 16° to 20° towards the south, and is much mixed with layers of 

 clay, which attain as much as a foot in thickness, and indicate the 

 relation of this quarry to those at Hillmarton. The limestone is 



