NOTES ON THE BRITISH JURASSIC BRACHIOPODA. 31 



forms are found were deposited in seas of very moderate 

 depths, there being no reason to believe that the same kind 

 of animals in past times lived under very dissimilar condi- 

 tions to those now existing. 



D, habeana, d'Orb. = I>. townshendi, Forbes, it may be 

 mentioned, is the sole representative of the Brachiopoda in 

 the Rhoetics of this country. 



Of the twelve species from the Jurassics, eight are found 

 in the Oolites. 



Localities. 



D. dundriensis (type), Moore, Inferior Oolite, Dundry. 



B. davidsoni (type), Moore, Lower Lias, Bedminster 

 Down. 



D. etheridgei, Dav., Inferior Oolite, Nailsworth, Gloucester- 

 shire. 



D. holdeni, Tate, Middle Lias, Cheltenham, Gloucestershire. 



D. davidsoni, orbicularis, rejiexa, and D. (?) moorei, have 

 been obtained from the Lias of the Ilminster district. 



The type specimens of D. davidsoni and D. dundriensis, both 

 collected and named by the late Chas. Moore, may be seen 

 in the Bath Museum (23). 



In my collection are two specimens of Discina, sp. nov., 

 which I collected some three or four years ago from the 

 Bradford clay of Bradford-on-Avon, Wilts, the first, I 

 believe, recorded in this country from that horizon. 



CRANIA, Retzius, 1781. 

 Etym. — KpavLov, a skull. 



Shell inartioulated ; no foramen, peduncle, or calcareous 

 supports ; fixed to marine bottoms by a portion of the sur- 

 face or substance of the lower or ventral valve. 



The species of this genus vary very greatly in shape and 



