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SUPPLEMENT TO THE BRITISH 



varietal one began. He adds that the same fact is observable in specimens from 

 Boulogne, Chatel Censoir, and many other places, and consequently he sees no necessity 

 for Oppel's varietal designation. 



Mr. Walker informs me that Mr. Seeley and himself have found in the Oxford Clay 

 at Elsworth (in a bed higher in position than the Kelloway rock), 1 specimens which 

 agree with Schubler's or Zieten's type. He thinks that as these last and Oppel's 

 variety occur with us in rocks of a different age there would be no harm in retaining 

 Oppel's named variety. We would therefore have — Terebratula insignis, Sckubler. 

 Dav. Sup., PI. XV, fig. 7 ; from Oxford Clay, at Elsworth and Nattheim. 



87. Var. Maltonensis, Oppel. Dav., Ool. Mon., p. 47, PI. XIII, fig. 1; and 

 Sup. PI. XV, figs. 5, 6 ; and Oppel • Die Jura-Formation,' p. 608. Erom the 

 Coral Rag, or Cidaris-florigemma-Zone at Appleton and Whitewall near Malton. 

 It occurs occasionally in one or two other Yorkshire localities. It is very rare 

 in the Coralline Oolite of North Grinston, near Malton, in the bed which contains 

 the fine Pseudodiadenia hemispharica, where it was discovered for the first time by 

 Mr. J. F. Walker. It is also met with in beds of a similar age at the Mont-des- 

 Bucardes, near Boulogne. Terebratula insignis is well described by D. Brauns at 

 p. 370 of his £ Der Obere Jura/ 1874. 



88. Terebratula Oxoniensis, Walker, MS. Sup., PI. XV, figs. 8, 9. 



Spec. Char. — Shell broadly oval, longer than wide. Sides slightly convex, some- 

 times nearly straight, front moderately raised in a biplicated rounded wave. Dorsal 

 valve convex, and biplicated from about the middle to the front. Ventral valve rather 

 deeper than the dorsal one, beak incurved, moderately produced, and truncated by a 

 circular foramen, slightly separated from the hinge-line by a deltidium in one piece. 

 Surface smooth, marked by concentric lines of growth. The loop in the interior of the 

 dorsal valve is short and simple. Proportions variable. 



Length 1 inch 4 lines ; breadth 1 inch 1 line; depth 10 lines. 



Obs. — This species is easily distinguished from T. insignis by its biplicated valves. 

 It is generally black and glossy, and occurs in the Oxford Clay at St. Ives in 

 Huntingdonshire, and some other places. 



1 « Annals and Nat. Hist.,' 1862. 



