24 PKOCEBDINGS OP THE GEOLOGICAL SGCIEIY. [jS"0V. 9, 



Section at WJiitehead. 



Thickness. 

 1. White limestone. ft. in. 



M r 2. White limestone with chloritic grains, yielding Ven- 



f^-fl "> ^ ^ J triculites 1 6 



P O [Sols. Soft chloritic calcareous sandstone in nodules 1 8 



\^^. 'Ba,ndi oi Ananchytes ovatus 2 



C^ ( o ( 

 •S g |:-S^ I 5. Soft greenish sands 3 9 



^ a \ o s=! •< 6. Fossil - bed marked by fragments of Inoceramus 



:2 S 2 02 I Crispi 1 



H o V I "^^ ^'^f* green sands, &c. 



The fossils of the Chloritic Sands are principally derived from the 

 band characterized by Inoceramus Crispi, which is a conspicuous 

 horizon in the eastern area. The characteristic species, arranged in 

 the order of their frequency, are : — 



Inoceramus Crispi. 

 Ostrea semiplana. 

 Terebratula obesa. 



carnea. 



Ehynchoner.a robusta. 



latissima. 



Ostrea canaliculata. 

 Pecten quinquecostatus. 



Spondylus spinosus. 

 Heteropora cryptopora. 

 Catopygus carinatus. 

 Serpula filiformis. 

 Pleurotomaria perspectiva. 

 Cidaris vesiculosa. 

 Epiaster distinctus. 



On tracing the Chloritic Sands to the west, some lithological dif- 

 ferences appear, accompanied by almost a new fauna. Thus to the 

 west of the Cave Hill the Chloritic Sands are generally represented 

 by compact siliceo-chloritic sandstones, with intervening bands of 

 soft sands. These sands are the fossiliferous portions pa?- excellence, 

 the dominant species being Eccogyra columba. 



These beds are exposed at the Black Mountain, Hanna's Town, 

 and near the bridge in Colin Glen. Succeeding a great development 

 of the yellow sandstones at the last-named locaHty, there occur 

 compact chloritic sandstones of a light-green colour, with two fossil- 

 bands in a softer sandstone, one below especially charged with Ver- 

 micularia concava, the other with ^'.rof/yra columba, with, y^hich. are 

 associated Cucrdlcea fibrosa , Trigonia Dcedalea, Pecten cequicostatus, 

 TValclheimia Hibernica, Ostrea semiplana, Ammonites Lewesiensis, 

 Corax falcatus, Otodus appendicadatus, PtycJiodus mammillaris, 

 Anatina Royana, Cardium gibbosum, Inoceramiis striatus. 



In the last-mentioned localities the Chloritic Chalk is wanting, 

 and the passage from the Chloritic Sandstones to the White Lime- 

 stone is abrupt. This is seen in a fine section by the waterfall in 

 Colin Glen, about half a mile above the bridge, the Chloritic Sand- 

 stones exhibiting in so short a distance a remarkable variation in 

 composition and fossils. 



