(50 — 



Tableau synoptique des IchthyodoruUthes. 



Grauwacke. Silurien. 



Onchus Murchisoni — Ludlow. 



» tenuistriatus — Ludlow. 



Old-Red. 



Onchus arcuatus — ■ Bromyard. 



» seinistriatus — Southstone-Rock. 

 Ctenacanthus ornatus. Pays de Galles. 



Houille. 



Onchus sulcatus — Cale, carbonif. Bristol. 



hamatus — Cale. carb. Bristol. 

 Ctenacanthus major — Cale. carb. Bristol. 



« tenuistriatus — Cale. carb. Bristol. 



>) brei^is — Cale. carb. Bristol. 

 Oracanthus Milleri — Cale. carb. Bristol. 



» pustulosus — Cale. carb. Bristol. 



» minor — Cale. carb. Bristol. 

 Gyracanthus formosus — Burdie-House , Neweastle , Sunderlaiid , 



Alnwick, Burnt-lsland. 



» tuberculatus — Sunderland . 



j) alnwicensis — Alnwick Castle. 

 Tristychîus arcuatus — Greenside près de Glascow. 

 Ptychacanthus sublevis — Burdie-House. 

 Sphenacanthus serrulatus —'^arâie-U.ouse. 

 Pleuracanthus lœvissîmus — Dudiey. 



MuSCHELKALR. 



Hybodus major — Lunéville, Bayreuth, Breslau. 



» tennis — Lunéville, Bayreuth. 



n dimidiatus — Lunéville. 

 Leiacanthus falcatus — Lunéville, Bayreuth. 

 ToM. m. 10 



