630 



MR. R. D. VERNON ON THE GEOLOGY AND [DoC. I9I 



Two distinct faunas, which never commingle, are represented ; 

 one of these appears to be marine, and the other is of freshwater 

 habitat. 



The freshwater lamellibranchiata. — A large number of 

 shells have been obtained, chiefly from the roof of the Thick Coal 

 or from the uppermost subdivision of that seam, the Two-Yard or 

 Four-Feet Coal. The following general section of the strata 

 forming the roof of this coal shows the mode of occurrence of the 

 shells : — 



/^(3) Rock. (A hard grey sandstone.) 

 J (2) Grey sandy shale, with small nodules of ironstone. 

 I (1) Black laminated carbonaceous shale. 

 I Two-rard Coal. 



The black shale (1) is a prolific horizon for the genus Oarhonicola — 

 indeed, so abundant are these fossils in the shale and so constantly 

 does this ' mussel-band ' occur at this horizon throughout the coal- 

 field, that it may be used as an index for the identification of the 

 coal. Shells of this genus also occur, but more sparingly in the 

 grey shales (2) and in the nodules of ironstone contained therein. 

 But, while the specimens from the latter bed appear in the form of 

 internal casts in ironstone and are generally very small, those from 

 the former have the periostracum preserved and are usually much 

 larger and apparently more robust. This fossil horizon has been 

 detected at the following nine collieries : — 



Collierf/. Horizon. 



Arley Ryder Coal. 



Baddeslej'^ Ryder Coal, 



Binley Thick Coal. 



Kingsbury Ryder Coal. 



Newdisate Thick Coal. 



Colliery. Horizon. 



Nuneaton Thick Coal. 



Stockingford ... Thick Coal. 



Tunnel Thick Coal. 



Wyken Thick Coal. 



The fossils which have been obtained from the foregoing localities 

 are recorded in the following list : — 



Species. 



Occurrence. 



Carhonicola aquilina (Sow.). 

 Carhonicola similis (Brown). 

 Carhonicola obtusa Hind. 

 Carhonicola turgida (Brown). 

 Naiadites earinata (Sow.). 



Anthracomya toiUiamsoni (Brown). 



Constant throughout the coalfield. 



Kingsbury Collier3'. 



Kingsbury Colliery ; Tunnel Colliery. 



Binley Colliery ; Tunnel Colliery. 



Arley Colliery : Griff Clara Colliery- ; 

 Tunnel Colliery. 



Kingsburj' Collierj- ; Baddosley Col- 

 liery. 



