PLATE XXX. 



CARBON IEEROUS SPECIES. 



Fig. 



1 . Orthis resupinata, Martin. Carboniferous limestone, Millecent, Ireland. 



V. Portion of the surface, enlarged. 



2. ,, ,, Interior of the dorsal valve, Derbyshire. 



3. „ „ Interior of the ventral valve, a, Occlusor; r, divaricator, 



muscular impressions. Both 2 and 3 belong to the 

 same specimen. 



4. „ ,, Interior of the dorsal valve, a, Adductor or occlusor mus- 



cular impressions ; j, cardinal process. Carboniferous 

 shales, Ulverston, Lincolnshire. 



5. „ „ Interior or ventral valve, shales near Settle. 



(>, 7, S, 9. Orthis Michelini, L'Eveille. 6. From the Carboniferous shales of Clat- 

 tering Dykes, Malham Moor, Yorkshire. 

 7. From shales, Gateside, near Beith, 

 Scotland. 8, 9. From Carboniferous 

 limestone, Millecent, Ireland. 

 10. ,, ,, Interior of the dorsal valve (enlarged), j, Cardinal process ; 



a, adductor or occlusor muscular impressions. Gateside, 

 Ayrshire. 

 II- ,, ,, Interior of the ventral valve (enlarged), same locality, a, 



Adductor or occlusor ; r, cardinal or divaricator, muscular 

 impressions. Mr. Hancock is of opinion that the upper 

 portion of this impression, or that nearest the beak, may 

 belong to the ventral adjustor, and that n may also 

 perhaps be caused by the pedicle, o, Ovarian spaces. 



12. ,, ,, r Carboniferous limestone, Settle, Yorkshire. A similar shell 



to this is described under 0. Michelini by Prof, 

 de Koninck, in his work on the ' Animaux fossiles 

 de la Belgique,' pi. xiii, fig. 8, but was afterwards 

 believed to be, perhaps, different. Having examined 

 many examples, I am disposed to consider it only a 

 slightly modified condition of L'Eveille's species. 



13. Sfreptorhynchus crenistria, var. senilis. A very globose example, from the 



Carboniferous limestone of Bowertrapping, near 

 Dairy, in Ayrshire, and collection of Mr. J. 

 Thomson. 



14. „ „ var. senilis (deprived of its outer surface or sculp- 



ture). From the Carboniferous limestone of 

 Settle, Yorkshire. 

 15- „ „ This is the valve described as Lcptcena anomala, 



Sow., in pi. 615, fig. l''(not"> c or (/ ) of the 'Mine- 

 ral Conchology,' and as Strophalosia striata 

 by Prof. Morris, at p. 155 of his 'Cata- 

 logue ;' but an attentive study of the 

 specimen and of other similar examples has 

 convinced me that it is none other than an 

 imperfect, contorted valve of S. senilis, of 

 which the outer layer or sculpture has been 

 obliterated. Traces of the stria? may, however, 

 be noticed here and there upon its surface. 



