on new species of Fossil Chimceroid Fishes. 53 



angle of the dental edge 1 inch 1 line ; dental edge 1 inch 7 lines ; 

 anterior division 1 inch ; posterior division 7 lines ; heel (mutilated) 

 7 lines ; exterior flat, marked by fine vertical striae ; depression at 

 the heel circular, deep and broad ; dental edge deeply indented in 

 the form of two semicircles ; symphysis straight. Stratum, great 

 oolite : locality, Stonesfield. 



7. C. rugulosa. — Maxillary plate, left lower jaw : length 1 inch ; 

 depth at the symphysis 4 lines ; ditto at the medial angle of the 

 dental edge 3 lines ; dental edge 6£ lines ; anterior division 3 lines ; 

 posterior ditto 3| lines ; heel 3^ lines ; exterior rugose ; one strong 

 depression near the heel striated vertically ; anterior division of the 

 dental edge concave ; posterior ditto ditto nearly straight. Inner 

 surface : triturating tubercles placed very obliquely. Stratum, great 

 oolite : locality, Stonesfield. 



8. C. helvetica. — Maxillary plate, right lower jaw : length 2 inches 

 5 lines ; depth at the symphysis 1 inch 4 lines ; anterior division of 

 the dental edge 1 inch 4 lines ; breadth of ditto 8 lines. This spe- 

 cimen being much mutilated, the measurements are incomplete. 

 It approaches more nearly to C. Mantelli than to any other species. 

 Stratum, molasse : locality, CEtmaringen, canton of Argovie. 



9. C. Dutelrii. — Maxillary plate, left lower jaw : length 4 inches ; 

 depth at the symphysis 2 inches 2 lines ; breadth of ditto 7 lines ; 

 depth at the medial angle of the dental edge 2 inches 2 lines ; dental 

 edge 3 inches 6 lines ; anterior division of ditto 1 inch 8 lines ; width 

 of ditto 8 lines ; posterior division of ditto 1 inch 8 lines. This tooth 

 is broad and strong ; the exterior is marked with indistinct undu- 

 lations ; the depression at the heel is nearly horizontal. Inner sur- 

 face : symphysis rather oblique ; the triturating tubercles broad, and 

 worn down less obliquely than in C. Townsendi, to which species this 

 most nearly approximates. Stratum, Kimmeridge clay : locality, 

 Boulogne. 



10. C. Beaumonti. — Maxillary plate, right upper jaw : length of 

 the outer margin 3 inches 5 lines ; length of the inner ditto 2 inches 

 8 lines ; breadth at the base 1 inch 6 lines ; depth of the symphysis 

 5 lines ; breadth of the principal tubercle 6 lines ; the upper surface 

 is marked by a deep sulcus, 7 lines in width, running parallel with 

 the symphysis ; the inner surface has four triturating prominences, 

 one anterior, two basal, and one intermediate. Stratum, Kimme- 

 ridge clay : locality, Boulogne. 



1 1. C. Dufrenoyi. — Maxillary plate, left lower jaw; length 2 inches 

 4 lines ; depth at the symphysis 1 inch 1 line ; ditto at the medial 

 angle of the dental edge 1 inch 4 lines ; dental edge 1 inch 5 lines ; 

 anterior division of ditto 7 lines ; breadth of ditto 5 lines ; posterior <■ 

 division of ditto 8 lines ; heel 1 inch ; exterior slightly concave and 

 uneven ; inner surface contracts rapidly in diameter in the direction 

 of the base ; anterior tubercle 1 inch 6 lines in length by 6 lines in 

 breadth, placed very obliquely ; posterior tubercle small and narrow. 

 Stratum, Kimmeridge : locality, Boulogne. 



The author then enters into a detailed comparison of the fossil 

 Chimeeroids with the recent genera Chimccra and Callorhynchus, and 



