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SUPPLEMENT TO THE BRITISH 



Society. I quite agree with M. Pictet that, as Zieten had previously (in 1830) 1 applied 

 the name Terebtahula longa to another, although apparently closely allied, species^ 

 Roomer's name cannot be retained for the shell under description ; and, as I believe 

 Sowerby's T. faba to be a Terebratula, the designation of Waldheimia faba, d'Orbigny, 

 sp., might be retained as a substitute for that of Ter. longa. 



Waldheimia faba varies considerably in shape, principally on account of the absence 

 or presence of a median depression in the anterior portion of the smaller or dorsal- 

 valve. I am quite certain that d'Orbigny's and Roemer's species are the same; for 

 I possess French specimens given to me by Alcide d'Orbigny in 1848, which entirely 

 agree with others from the Hils formation of Germany. 



Position and Locality. — W.faba occurs in the Middle Neocomian or Speeton Clay at 

 Knapton, in Yorkshire : the specimen figured in Sup., PI. VI, fig. 12, agreeing in every 

 respect with some of Roemer's examples, was lent to me many years ago by the late 

 Mr. Bean. It has been found likewise in the Middle Neocomian at Acre House, near 

 Tealby, where several good examples have been obtained by Mr. Judd. 



Waldheimia faba (T. longa, Roemer) is a common fossil in the " Elligser Brinke 

 Schiefer" (Middle Neocomian), near Delligsen, Hanover. In France it is quoted by 

 d'Orbigny from Saint-Dizier (Haute-Marne), and by M. Pictet from the Yellow Neocomian 

 (Middle Neocomian) of Locle, in Switzerland. 



RHYNCHONELLIDiE. 



On account of the very great variation in shape assumed by almost every species of 

 the genus Rhgnchonella, it becomes no easy matter to find characters sufficiently constant 

 by which they can be clearly separated. 



I have ventured to divide the British Cretaceous Rhgnchonella into twenty-two 

 species ; but it is possible that two or three of them should be considered as varieties of 

 some of the others. 



About half the number are peculiar to the Cretaceous deposits above the Gault, 

 and the other half occur in the Lower Greensand or Neocomian. Very few, if any, 

 of the British Cretaceous Rhgnchonella; appear with certainty to be common to the 

 two periods. 



1 • Die Verst. Wurttembergs,' pi. xxxix, fig. 7- 



