268 



JURASSIC. 



of limestones.^ At Barrow-on-Soar the zone of Ammonites angu- 

 lalus is represented by 12 feet of blue clays. 



The cuttings on the Syston and Peterborough Railway, between 

 Kirby and Whissendine, exhibit several divisions of the Lower 

 Lias. The following divisions have been noted by Prof. Judd 

 in that district:- — 



Zones. 

 A. capricoriius m. Blue clays with much pyrites and many septaiia. 



Ammonites capricorniis, Pentacrijius robuslus. Galley 

 Hill, Neville-Holt, Little Bovvden. 



A. ibex? /. Clays with septaria, and thin sandy layers. A. latcEcosfa, 



A. brevispuia, A. yamesoni, etc. Stapleford Park, Little 

 Dalby. 



Clays with shelly limestones with Cardinia attenuata, 

 Hippopodium poiiderosum. Dalby, Staunton Wyville. 



Blue laminated pyritous shales, with thin bands of limestone. 



Am?nonitcs bipiinctatns, Spirifera IValcotiii, PentacrinuSy 



etc. Saxby, Thorpe Langton. 



Sandy clays with stone-beds. Loseby. 



Clay with much pyrites (producing selenite by its decom- 

 position), and small septaria. Beleinnites clavatus, Plicatula 

 spinosa. Freeby. 



Ferruginous limestone, Ammonites semicosiatus, Cardinia 

 Listeri, Gryphaa incnrva. Vale of Belvoir. 



Blue clay with Grypluea incnrva. (Well at Stapleford Park.) 



Clay with bands of pyrites, Ammonites angnlatus. Barrow- 

 on-Soar. 



Coarse-grained and shelly limestones, Am?nonites planorbis. 

 Nautilus striatus, Lima gigantea. Sysonby. 



' Fish and Insect Limestone,' finely laminated argillaceous 

 limestone alternating with shale, and abounding with re- 

 mains of fish, crustaceans, saurians, plants, and sometimes 

 insects. Extensively worked at Granby, BaiTow-on-Soar, 

 etc., for the manufacture of hydraulic cement. Prof. Judd 

 suggests that these beds be called the ' Strensham series,' 

 from the village of that name east of Upton-on-Severn, 

 in Worcestershire, where the beds were hrst studied by 

 the Rev. P. B. Brodie. 



A. yamesoni .... 



A. armatus 



A. oxynotus 



A. semicostatns 



A. Bucklandi.... 

 A. angnlatus .... 



A. planorbis 



I k. 





With regard to the zone of ^. obtusus. Prof. Judd observes that the beds at this 

 horizon in the district are very obscure, and if they exist they are nowhere well 

 exposed. 



In Northamptonshire the Lower Lias has a thickness of about 

 650 feet ; and in Lincolnshire the thickness is at least 400 feet. 



In the north-west of Lincolnshire, at Frodingham and Appleby, 

 there is a valuable bed of ironstone 27 feet thick, covering the wide 

 plain on which is situated the village of Scunthorpe ; this bed has 

 been largely worked.^ It occurs low down in the Lower Lias, in 

 the zone of Anunonites semicosiatus, and at Redmile and other places 

 in the Vale of Belvoir this zone is represented by ferruginous stone. 

 At Bracebridge and Waddington, near Lincoln, the clays with 



1 H. E. Quilter, G. Mag. 1886, p, 59. 



- Geology of Rutland, etc. p. 58. In reference to the Insect Fauna, see Brodie, 

 Fossil Insects (1845) ; H. Goss, P. Geol. Assoc, vi. 116. 

 ^ Rev. J. E. Cross, Q. J. xxxi. 119. 



