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SUPPLEMENT TO THE BRITISH 



Sp. Hartmanni, and Sp.pinguis, and is more pentagonal. There exists also a well-defined 

 mesial fold in the dorsal valve and sinus in the ventral one, with from four to seven 

 small rounded ribs on each of the lateral portions of both valves. The fold is also some- 

 times marked or longitudinally divided by a shallow groove. The spines which cover 

 the surface of both valves are short, strong, and comparatively less numerous than in the 

 three species already named. The spiral supports approach most in their shape and 

 direction to those of Sp. rostrata, and have a smaller number of coils (Sup., PJ. XI fig 

 10). 



Sp. verrucosa is tolerably abundant in the Middle Lias, and occurs in those beds 

 characterised by Waldheimia numismalis. In England it is found in the Marlstone of 

 South Petherton, near Ilminster, and is stated by Mr. R. Tate 1 to characterise the zone of 

 Am. Jamesoni, at Cheltenham, Aston, &c, in North Gloucestershire. It is the Sp. medicevies 

 of Simpson, who quotes it from the Lower Lias of the Peak in Yorkshire. It is mentioned 

 by Bryce and Tate from the Am. armatus and Am. Jamesoni beds of Raasay, in the north 

 of Scotland, also from Hallaig in the island of Skye. In France it is common in the 

 Middle Lias at Metz, A vallon, Besancon, Salins, &c, and is especially abundant in various 

 localities in Normandy. It occurs in the Middle Lias of Pliensbach, near Boll. 



37. Spiriferina Walcotti, Sow. Dav., Ool. Mon., p. 25, PI. Ill, figs. 2, 3. 



Spiriferina Walcotti is stated by Mr. R. Tate to occur in the Lower Lias or Zone of 

 Am. Bucklandi, Am. Turneri, Am. oxynotus, and Am. raricostatus. Also in the Middle 

 Lias or zones of Am. margaritatus and Am. spinatus. Mr. E. B. Tawney, in some inter- 

 esting notes on the Lias, 2 minutely describes the geological position of Spiriferina 

 Walcotti in the neighbourhood of Radstock, where it is restricted to the Lower Lias. 

 The shell was also collected by Captain E. J. Bedford, R.N., in the Middle Lias shales 

 at Caisaig Bay in the Island of Mull, by Messrs. Bryce and R. Tate, from a similar rock 

 at Hallaig and Raasay in the north of Scotland, and by Mr. J. Thomson from the 

 Middle Lias in the Bay of Lussay, four miles from Bradford in the Island of Skye, as 

 well as in the Island of Pabba. It appears also not to be very rare in the zone of 

 Am. Bucklandi at Redcar, and Robin Hood's Bay, in Yorkshire. The Spirifer latus 

 of Martin, Sp. recentior and Sp. liasicus, of Simpson, are all considered by Mr. R. Tate 

 as synonyms of Sp. Walcotti. 



1 'Geological Magazine,' vol. v, p. 552, Dec, 1869. 



2 ' Bristol Naturalists' Society's Proceedings,' vol. i, part 2, 1874. 



