﻿JURASSIC AND TRIASSIC BRACHIOPODA. 



89 



Genus Crania, Retzius. 



20. Crania Moorei, Dav. Dav., Ool. Mon., p. 12, PI. I, fig. 0. 

 Nothing new to be added. Upper Lias, Ilminster. 



21. Crania antiquior, Jelly. Dav., Ool. Mon., p. 11, PI. I, figs. 4 — 8, and Sup., 



Pi. IX, figs. 36, 37. 



Cbania Ponsorti, E. Deslonych. C. Moore, Geologist, vol. iv, p. 98, pi. ii, figs. 9, 10, 



1861. 



It is quite true that the external surface of the larger number of specimens of C. 

 antiquior is very irregular, rugose, or coarsely wrinkled, but exceptionally well preserved 

 specimens are occasionally found in which the surface is more regularly patelliform, 

 with, here and there, a tendency to rudimentary obscure plication (Sup., PI. IX, fig. 36), 

 or squamose concentric lamelliform projections, which at times become almost spinose 

 (fig. 37). In this last-named condition the shell would agree with the description given 

 by Mr. E. Deslongchamps to his Crania Ponsorti (Annuaire de PInstitut de France, 

 1855), to which species (?) Mr. C. Moore has referred the specimen, figs. 36 and 37 

 of our plate. These two exceptional examples were found in the same bed, accompa- 

 nied by the common forms of C. antiquior. Mr. Moore does not fail, however, to 

 state, " After examining many examples of the C. antiquior, I have observed in some of 

 them a tendency to become more rugose and to pass gradually into the form represented 

 by the above shell, and I am therefore disposed to consider it {Crania Ponsorti) only as 

 a variety of C. antiquior?'' He adds likewise that " the interior of C. Ponsorti appears 

 undistinguishable from the interior of C. antiquior." 



I have never seen French specimens of Mr. E. Deslongchamps' C. Ponsorti, which, 

 according to that distinguished palaeontologist, differ from C. antiquior by their squamose 

 external surface. Both forms, however, are found together in the Great Oolite of St. 

 Aubin-de-Langrune in Normandy, and in England at Hampton Cliff, Bath. I have also 

 met with a very fine example of C. antiquior in the Great Oolite of Ranville, near Caen. 



22. Crania Saundersii, Moore. Sup., PI. IX, figs. 38 and 39. 



Crania Saundehsii, Moore. The Geologist, vol. iv, p. 98, pi. ii, figs. 11, 12, 1861. 



Of this species the unattached valve only has been found. The two examples forwarded 



12 



