ESTHERIA MINUTA. 59 



At the canal-tunnel in 



Red marl 30 to 40 feet thick ) 



Keuper I Fossiliferous sandstone and green marl ... 20 „ ( Slirew iey Common. 



i, Red and variegated marl 10 „ J 



( Calcareous band, 



Bunter Sandstone; 1 occurring at Ambersley, Bromsgrove, and Warwick; also in Cheshire and 

 Shropshire (Grinshill, Hawkestone). 



After pointing out the uniform extent of the Keuper Sandstone throughout Wor- 

 cestershire, Gloucestershire, and Warwickshire, and in which occurs the so-called 

 Posidonomya minuta, they remark (p. 337) — 



" The exact geological position of this sandstone, which we consider to be the 

 equivalent of the Keuper Sandstone of Suabia and Alsace, is 200 or 300 feet below the 

 lowest beds of the Lias — a position which coincides well with that of the principal mass 

 of this sandstone in Wurtemberg, where one of the authors has examined it. In Germany, 

 however, the Keuper formation contains several courses of sandstone and grit, but always 

 subordinate to thick masses of marl. In England, we have one well-defined band only, 

 which, occurring from 200 to 300 feet below the Lias, is completely and distinctly 

 separated from the Great Red Sandstone of the central counties by a vast thickness of 

 red and green marls, which in certain tracts are saliferous. .... 



" The Keuper of England (on the whole quite as largely developed as that of Germany) 

 is, like the ' Marnes Irisees ' of France, a great marly formation, with one principal band 

 of sandstone 2 subordinate to it, which sandstone is separated by at least 600 feet of 

 marls from the great mass of the underlying New Red Sandstone (Bunter Sandstone)." 

 In speaking of Est her i a minuta, which occurs at Shrewley Common, in company with 

 the spine of Hybodus Keuperiamis (termed Keuperinus, at p. 388), "two small teeth of 

 squaloid fish," reptilian foot-tracks, and ripple-mark, they say (p. 338) 



" The bivalve shells (pi. 28, fig. 4 ) appear to be the Posidonomya minuta of 

 Bronn ('Lethsea Geognostica,' p. 164, pi. 11, fig. 22), or the Posidonia minuta of 

 Goldfuss (' Petrefacten,' pi. 113, fig. 5), and of Zicten (' Versteinerungen Wurttem- 

 bergs,' pi. 54, fig. 5)." 3 



And they proceed to observe that — 



" In Germany this shell is stated to pervade 4 the New Red system from the ' Keuper' 

 to the ' Bunter Sandstein ' inclusive ; but in this country it appears peculiar to that 

 band of sandstone which we have proved by stratigraphical evidence to represent the 

 upper formation. It is indeed a very characteristic shell ; for, as previously stated, we 



1 The more modern and correct classification of these beds is given further on, at p. 62. 



2 See Mr. Hull's remarks on the Keuper Sandstone of the Midland Counties further on, p. 64. 



3 " Bronn has changed the generic name to Posidonomya, the term Posidonia being preoccupied in 

 botany. Capt. Portlock has lately detected this shell in the New Red Sandstone of Roan Hill, near 

 Dungannon, Ireland." (See p. 40 of tins monograph.) 



4 This is not correct ; see the account of the German Trias above, pp. 46 et seq. 



