1862.] 



KIRKBT FOSSIL CHITONS. 



237 



Two years after this, in 1845, Baron do Ryekholt described ten new 

 species from the same formation, in a paper that appeared in the 

 * Bulletins de I'Academie Eoyale de Bruxelles ' (tome xii. no. 7). In 

 1847 the same author noticed another species, which he referred to 

 Chitonellus, in the ' Bulletins de I'Academie Royale de Belgique ' 

 (tome xxiv. p. 63). Lastly, a species was described by Mr. W. H. 

 Baily, of the Geological Survey, in 1859, from the Carboniferous 

 Limestone of Ireland, in the •' Dublin Natural History Review, 'vol. viii., 

 and * Journ, Geol. Soc. Dublin,' vol. viii. p. 167. 



The latter author has also recently published an annotated trans- 

 lation of an old though interesting paper by Professor De Koninck, 

 on two Silurian species of this genus, in which is given a short 

 sketch of all that had been done in the palaeontology of the Chito- 

 nidce up to the date of publication of the paper ; the sketch being 

 accompanied by a list of fossil Chitons from the Lower Silurian to 

 the Upper Tertiary, and Mr. Baily having increased its value by adding 

 to it the results of recent discoveries. Both in this list, however, 

 and in the one originally published by De Koninck, several of De 

 Ryckholt's species are considered but varieties of those described 

 by De Koninck, or altogether ignored ; hence, instead of eleven, 

 only three of De E-yckholt's species are allowed in these lists. It is 

 quite possible that Professor De Koninck may be right, to some ex- 

 tent, in considering certain of De Ryckholt's species to be only 

 varieties of his own, but, so far as may be judged from the descrip- 

 tions and figures of the forms described by the latter author in his 

 valuable paper in the ' Bulletins of the Royal Academy of Brussels,' 

 I see no reason for adopting so sweeping a criticism as that which 

 De Koninck has virtually passed upon De Ryckholt's species ; for, 

 though I have had but slight opportunities of examining specimens 

 from Belgium, there seems evidence enough in the figures of De 

 Ryckholt to show that other forms, besides the three allowed by 

 De Koninck, possess peculiar characters of specific value. I include 

 therefore, in the following list of the Carboniferous species of this 

 family, aU those described as such by Baron de Ryckholt ; it being, 

 in my opinion, only fair to that palaeontologist to acknowledge his 

 species until we have shown them to be unworthy of such distinction. 



List of Chitones from the Carboniferous Rocks. 



11. Chiton Eburonicus, DeByck. 



12. Sluceanus, De RycJc. 



13. Turnacianus, BeEyck. 



14. Thomondiensis, Baily. 



15. Burro wianus, Kirkby. 



16. coloratus, Kirkby. 



17. ?, spec. nov. 



18. spec. nov. (?). 



*19. ChitoneUus Barrandeanus, De 



Byckholt. 



* The Chitonellus cordifer, which Professor De Koninck doubtfully referred 

 to this family, has been shown by Baron De Ryckholt to belong to the Crinoidea. 



1. Chiton priscus, Miinster. 



2. gemmatiis, Be Koninck. 



3. concentricus, Be Ko7i. 



4. Tornacicola, Be Byckholt. 



5. Scaldianus, BeByck. 



6. Nervicanus, Be Byck. 



7. Mempiscus, Be Byck. 



8. Mosensis, Be Byck. 



9. Viseticola, Be Byck. 



10. Legiacus, Be Byck. 



