﻿JURASSIC AND TRTASSIC BRACIIIOPODA. 



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18. Discina? annulosa, Dav. Sup., PI, X, figs. 15, and 15 a, b. 



Shell circular, very conical and elevated, vertex almost central, surface of upper 

 valve ornamented with five or more prominent ring-like ridges. Length and width about 

 3 lines ; elevation of upper valve about 2 lines. 



Obs. — I have seen one example of this species, which Mr. Leckenby obtained 

 from the Cornbrash of Scarborough. The type is now in the Woodwardian Museum, 

 Cambridge. 



19. Discina Babeana, d'Orb. sp. Dav., Ool. Mon., p. 9, PI. 1, figs. 2 a, b, and Sup., 



PI. X, figs. 21 to 24. 



Orbiculoidea Babeana, d'Orb. Prodrome, vol. i, p. 221, 1849. 



Orbicula Townshendi, Forbes, MS. Dav., Ool. Mon., p. 7, pi. i, figs. 2, 2 a, b, June, 



1851 ; Discina Townshendi, Dav., Ool. Mon., 



Appendix, p. 14. 



Discina Babeana, E. Desl. Etudes critiques sur des Brachiopodes nouveaux ou peu 



connus, p. 22, pi. iv, figs. 1 — 4, 1862. 



At page 14 of the ' Appendix ' to the first volume of this work, I intimated that 

 it was possible the Discina Toiunshendi of Forbes might require to be united with the 

 Discina {Orbicidoidea) Babeana of D'Orbigny, notwithstanding that the French examples 

 I had examined were very much more convex than the single British specimen then 

 known. Since that period Mr. Charles Moore has obtained from Rhaetic beds of 

 England some specimens showing a much more elevated upper or unattached valve than 

 is seen in the typical example of the so termed D. Townshendi, and so entirely agreeing 

 in dimensions, shape, and character with D'Orbigny's D. Babeana, that I cannot avoid 

 admitting the French author's priority. D'Orbigny describes his fossil in the following 

 words : — " Espece de 40 millim. de diametre, conique, lisse, a sommet lateral." No 

 figure accompanies this very brief description, but the shell is very well known to French 

 Palaeontologists, and is so labelled in all their collections. The diameter of forty 

 millimetres (=19 lines), given to the French type is exactly that of the type of the 

 British D. Townshendi, and 1 have noticed that the French species, of which I have several 

 examples before me, varies considerably in the degree of convexity or elevation of its 

 upper or larger valve. 



In 1862 Mr. E. Deslongchamps described and illustrated with great minuteness 

 D'Orbigny's species, and intimated at the same time, as I also had previously, that 



