ON NEW BRACHIOPODA. 163 



the development of tlie loop as in TerehratcUa Biichmanü. 

 The fact of the shell under conslderation proving to be a 

 Terebratella at once suggested the possibility that Terelra- 

 tula cardium might also belong to that genus ; and I learnt 

 from Mr. Davidson that he could not speak positivelj on 

 this point, as the shell from which his interior was figured 

 was not clear of the matrix, and only partially exhibited 

 the loop. I have taken much trouble to establish the 

 correct position of the T. cardiinn ; and after the examina- 

 tion and dissection of many apecimens, am able to say that 

 the loop, as figured by Mr. Davidson, is correct. This 

 species must therefore remain in its present position, but 

 the examples supposed to be its young forras will have to 

 be placed under Terebratella ; and, retaining Sowerby's 

 original specific name, must be called Terebratella furcata. 

 Two species of this genus are therefore added to British 

 Jurassic beds, and the Terehratula hcmisphcerica, which was 

 supposed to represent it in this age, removed. I have 

 obtained a portion of the interior of a small brachiopod, 

 showing a mesial septum, from the Upper Lias, ncar 

 Ilminster, which convinces me that the genus may also be 

 found in that formation. 



TEEEBEATULINA. 



Terebratulina radiata, Moore. 



PL L, figs. 11-14. 



Shell small, nearly as broad as long ; thickest near the 



umbo, and thinning gradually to the front and sides ; front 



roundcd ; valvcs convex, flattened, with numerous fine 



striations; foramen large, roundcd; area flattened; the 



exterior of the ventral valve shovvs a mesial depression, 



with a corresponding elevation in the interior of the valve. 



