PLATE XII. 



(Carboniferous Species.) 



1, 2. Spirifera glabra, Martin. Unusual varieties from Bolland. In the collections of 



Messrs. J. de C. Sowerby and Muschen. 



3. — — Var. with obscurely marked ribs on the lateral portions of the 



shell. Bolland. 



4, 5. — — Var. linguifera, Phillips. Fig. 4, from the original specimen 



represented in the ' Geology of Yorkshire/ and now in the 

 British Museum; 5, from the cabinet of Professor 

 Phillips. 

 6, 7. — rhomboidea, M'Coy. Pig. 6, from the original specimen figured in 



the ' Synopsis,' coll. of Mr. Griffith ; 7, from Millecent, 

 Ireland. 

 8, 9. — glabra, ? Var. from Lowick. Fig. 9, in the collection of Mr. Tate, of 



Alnwick. 



10. — ? ■ From Yorkshire, in the cabinet of Mr. E. Wood. Figs. 8, 9, 



10, are very unusual shapes, and it is with considerable 

 hesitation that they are referred to. Sp. Glabra, of 

 Martin. 



11, 12. — — Var. decora, Phillips. Fig. 11 is taken from the represen- 



tation published in the ' Geology of Yorkshire;' 12, from 

 a very fine specimen from Bolland, in the collection of 

 Mr. Muschen, of Birmingham, and every variation in 

 shape may be found connecting this specimen to the 

 normal shape of Sj). glabra. 

 13, 14. — uRii, Fleming. From the carboniferous shales of Carluke, Lanark- 



shire. 14 a, b, c, d, e, are enlarged representations. 

 15, 16. — stringocephaloides, M'Coy. Fig. 15, from the representation pub- 



lished in the 'Synopsis;' 16, from Leighlin, 

 Ireland, in the Museum of the Royal Dublin 

 Society. It is probable that these specimens 

 belong to exceptional varieties of Sp. lineata, 

 Martin. 



