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SUPPLEMENT TO THE BRITISH 



D. Babcana bears much resemblance to B. Townshendi ; he thought, however 3 that the 

 greater elevation of the larger valve of T. Babcana might perhaps distinguish it from the 

 British shell, but Mr. Moore's discovery of intermediate forms uniting the two- 

 obliges us to dispense with the name given to the English fossil by the late Edward 

 Forbes. 



In France B. Babcana occurs abundantly in a light yellow friable sandstone, 

 attributed by D'Orbigny to the base of the Lower Lias, near Langres (Haute Marne), 

 and I have it likewise from the same formation at Gortes (Cote D'Or). 



These sandstones which some French Geologists place in the " Infra-lias " would, 

 correspond to the Rhaetic formation, or to those beds which contain the Avicula contorta. 



At the period I described the so-termed Orbicula or Biscina Toionshendi nothing 

 positive was known by the Geological Survey with respect either to the geological 

 position or locality from whence their magnificent and perfect bivalve example had been 

 obtained; but I was informed by Mr. Walton, and subsequently (on the 16th of 

 January, I860) by the Rev. P. B. Brodie, that the late Mr. Townshencl, who resided at 

 Gloucester had found the specimen, now in the Survey Museum, lying loose among the 

 debris at Fretherne Cliff (Gloucestershire), and that he believed it to have been derived 

 from the Lower Lias ; but the specimen not having been found strictly speaking in situ, 

 and as Rhsetic beds occur at the Garden Cliff, some uncertainty may still prevail relative 

 to the age of the formation from whence it was derived. The Rhsetic formation is, 

 according to Lyell and others, composed of beds of passage between the Trias and the 

 Lower Lias, but these have not many species in common. 



In the fourth volume of the ' Geological Magazine ' (for 18G1, p. 99), Mr. C. Moore, 

 whose admirable researches among the Liassic and Rhsetic beds are known to every geologist, 

 informs us that having discovered this species (B. Townshendi) in situ, in the Avicula contorta 

 zone, at the base of the Lias near Taunton, he was enabled to settle its position, and that 

 Professor E. Suegs, of Vienna, informed him that he had likewise obtained the shell in 

 the Rhaetic beds of Austria, in which the Avicula contorta zone is included. 



Mr. C. Moore has found the species in beds of Rhaetic age at Vallis, Frome 1 (which 

 is a pretty little ravine in the Carboniferous Limestone). The specimens are from a bed 

 of conglomerate, which Mr. Moore believes may once have formed the Rhaetic shore ; and 

 they are there associated with the Avicula contorta^ as well as with scattered Vertebrata of 

 the Rhaetic period. The bed containing these fossils lies upon the Carboniferous Lime- 

 stone. Mr. Moore has likewise obtained a smaller valve from rocks of a similar age at 

 Beer Crowcombe. 



B. Babeana is the only Brachiopod hitherto discovered in the Rhaetic formation, or 

 Upper Trias, of Great Britain, and is one of the largest and finest species of the 

 genus. 



1 See C. Moore, " On Abnormal Conditions of Secondary Deposits when connected with the Somerset- 

 shire and South Wales Coal Basin," 'Quart. Journ. Geol. Soc.,' vol. xxiii, p. 490, 1867. 



