PLATE IV. 



(Carboniferous Species.) 



Fig. 



1. Simrifera bisulcata, var., Sowerby. Bolland. Collection of M. De Koninck. 



2. tkansiens, M'Coy. Taken from the ' Synopsis of Carboniferous Fossils of 



Ireland,' tab. xix, fig. 14. 



3. — duplicicosta, Phillips. This figure is taken from the ' Synopsis of Carbo- 



niferous Fossils of Ireland,' pi. xxii, fig. 12, where it is 

 described under the name of Sp. f areata, M'Coy, but is 

 evidently the same as duplicicosta. 



4. — — A var. with wide ribs, from Park Hill, Longnor; in the 



Museum of Practical Geology. 

 5 — 11. — — Varieties of age, as admitted by Professor Phillips and M. De 



Koninck. Fig. 5 is from Bolland, collection of Professor 

 Phillips; 6, 7, 9, 10 from Park Hill, Longnor, Derby- 

 shire, Museum of Practical Geology ; fig. 8, a very 

 elongated shape from Bolland ; fig. 11 is what Professor 

 M'Coy has described and illustrated as Sp. fasciculata 

 in tab. iii d, fig. 25, of the ' British Palaeozoic Fossils.' 



12. penguis, Sowerby ? Sp. paucicostata, M'Coy. These figures are taken 



from the 'British Palaeozoic Fossils,' pi. iii d, fig. 26. 

 Derbyshire ; in the Museum of Cambridge. It is proba- 

 bly a young shell of Sowerby's species. 



L3. mosquensis, Fischer. Derbyshire. Cambridge Museum. 



14. — From Little Ireland (Ireland). Collection of the Royal 



Dublin Society. (See also pi. ix, fig. 4.) 



1 5. humerqsa, Phillips. This illustration is drawn from the original specimen 



on which Professor Phillips founded his species. ' Geology 

 of Yorkshire,' vol. ii, pi. xi, fig. 8 ; and is from Greenhow 

 Hill. Collection of Professor Phillips. 



1 6. — A perfect example, in the collection of Mr. E. Wood, from the 



Wensleydale district, Yorkshire. (See also pi. ix, fig. 5.) 



