OBT Jj-OSBILS TRO^L A WELL-SINKING AT SWINDON. 



291 



2. Notes on the Fossils obtained from the Well-sinking at Swindox 

 By E. T. Newton, Esq., F.G.S. 



KiMEEiDGE Clay. 



From 8 feet to 72 feet, Kimeridge Clay was passed through, but, 

 only a few fossils were collected : thus between 10 feet and 16 feet 

 Hhynchonella inconstans, Sby., Ammonites cordatus, Sby., and Ostrea 

 deltoidea, Sby., were noticed ; at 45 feet Astarte and Thracia de- 

 'pressa, Sby., and from 45 feet to 52 feet Belemnites were met with. 



The earthy Limestone-bed with iron-shot grains, between 50 feet 

 and 50 1 feet, yielded : — 



Pecten lens ?, Sbi/. 



Perna, sp. 



Ostrea deltoidea, Sby. 



Astarte, sp. 



Myacites recurvus, Phil. 



, sp. 



Pholadomya protei ?, Ag. 

 Ammonites cordatus, «S%., var. ex- 

 cavatvis, >by. (=A. serratus, Sbt/.). 



rotundus, Sb?/. 



varicostatus, Buckl. 



Coral Rag. 



The series of alternating beds, from 72 feet to 112 feet, probably 

 represent the " Coral Rag," but no determinable fossils were ob- 

 tained from them, although there are indications of shells and pos- 

 sibly Echinoderm spines. 



Oxford Clay. 



The beds from 112 feet to 685 feet are, no doubt, correctly re- 

 ferred to the Oxford Clay ; but the occurrence in the lower parts of 

 Ammonites Kosnigi, and of an Ammonite which cannot be distin- 

 guished from some forms of Am. calloviensis, would seem to indicate 

 that these lower beds may be the equivalents of the Kellaways Rock. 

 For convenience of comparison, the fossils have been divided into 

 groups corresponding to changes in the nature of the strata. 



From 112 feet to 400 feet, chiefly clay :— 



Gryphaea dilatata, Sby. 



Pecten, sp. 



Pinna mitis, Phil. 



Area, sp. 



Goniomya v-scripta, Sby. 



Myacites recurvus, Phil. 



Nucula omata, Qiienst. 



Pholadomya, sp. 

 Trigonia irregularis, Seeb. 

 Alaria trifida, Phil. 

 Ammonites cordatus, Sby. 



, var. excavatus, Sby. (=A 



serratus, Sby.). 

 perarmatus, Sby, 



From 400 feet to 622 feet, chiefly clay, with bands of Septaria : — 



Anabacia orbulites, Lamx. 

 Serpula vertebralis, Sby. 

 Avicula insequivalvis, Sby. 



, sp. 



Gryphaea dilatata, Sby. 



bilobata, Sby. 



Inoceramus. 

 Pecten, sp. 

 Pinna mitis, Phil. 

 Ostrea, sp. 



Area Quenstedti, Lycett. 



, sp. 



Astarte carinata, Phil. 



ovata. Smith. 



Cardium, sp. 



Corbula, sp. 



Goniomya v-scripta, Sh/ 



Modiola, sp. 



Nucula ornata, Quenst 



Pholadomya, sp. 



