SUPPLEMENT.— GEOLOGICAL DETAILS. 



Oolite Limestones, and also the Inferior Oolite Sands as they had often been called . 

 In other words, it comprehended what has been termed by various authors "the 

 Inferior Oolite Series " — the strata which had been mapped by the Geological 

 Survey as "Inferior Oolite (G 5) " and " Midford Sands (G 4)." 



However, as the Ammonite-fauna of the various facies of the so-called " Midford 

 Sands " became known, it was found that though certain developments of these 

 Sands were rightly enough Inferior Oolite, yet other developments thereof 

 were really contemporaneous with deposits termed " Upper Lias." This accounts 

 for the appearance in this work of many species which properly belong to the 

 " Upper Lias " or what is termed the Toarcian stage. Strictly this work, though 

 it deals with Ammonites from strata which have usually been called Inferior Oolite 

 Limestone and Sands (or from their argillaceous equivalents) should be termed a 

 monograph of the Ammonites of the Toarcian (pars), of the Aalenian, of the Bajocian, 

 and of the Bathonian (pars) stages. 



The following table will illustrate this, and it will also show the hemeral 

 classification which gives the dates for their deposits. 



Stratigraphi 







cal Terms 

 used by the 



Hemeral Names. 



Full Title of Distinctive Fossil. 



A | Stratigraphiea] 

 Ag( - S - Terms. 



Geol. Survey 













disci . 



Oppelia (?) discus 











(coarctatie) . 



Dictyothyris coarctata . 







& 





(maxillatve) 



Terebratula maxillata . 







1 





subcontracti 



Macrocephalites subcontractus 



Parkinsonian 



AGE 





QQ 





/ 



fuscie . 

 zigzag . 



Oppelia fusca 

 Zigzagiceras zigzag 



Upper 



Pi 



'3 







Truellii 



Strigoceras Truellii 





Inferior 



^ 





. 



Garantiani . 



Strenoceras Garantianum 





Oolite 



pq 





O 



niortensis . 



Strenoceras niortense . 





J 



CO 



o , 



o 



Blagdeni 

 , Sauzei 

 Witchellix sp. 



Cxloceras Blagdeni . . . 



Emileia Sauzei 



Witchellia sp. . . J 



1 



1 SONNINIAN 



Middle J 6 

 Inferior [ # § jf 



•r" 



o 



■g 



Sonninise sp. 



Sonninia sp. 



AGE 



Oolite ifaa 



1 



discitze 



Hyperlioceras discites . 



J 



r 



48 



'rt 



concavi 



Ludwigella concava 



L ^ 



'o / 





bradfordensis 



Brasilia bradfordensis . . .' 





It a 



o ^ 





Murchisonx 



Ludwigia Murchisonse . . . 



LUDWIGIAN 



Lower .3 <u 



o 





scissi . 



Tmetoceras scissum 



AGE 



^Inferior I J %P 



® 



•tf 



opaliniformis 



Cypholioceras opaliniforme . 





Oolite j3 w 



*a 



6 



aalensis 



Pleydellia aalensis 





) J * 





w 



Moorei 



Dumortieria Moorei . . . 











1 



Dumortierix sp. . 



sp. .... 





Upper 







CQ 



dispansi 



Phlyseogrammoceras dispansum . 





Lias, 



1 





"P 



StrucJcmarmi 



Pseudogrammoceras Struckmanni . 





Sensu 





O 



i striatuli 



Grammoceras striatidum 



Harpocera- 



t lato = 



cc 





1 



variabilis . 



Haugia variabilis . . . .' 



TAN AGE 



Upper 



'.I 





Lilli . 



Lillia Lilli .....' 





Lias, 



H 





bifrontis 



Hildoceras bifrons 





Oppel, 



1 





falciferi 



Harpoceras falciferu . 





etc. 



Eh 





acuti . 



Arieticeras (?) acutum. . .1 





J 





