378 



Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 



The second specimen is from Oretorp; less than half the size of the one 

 described. The surface of the crown is flat, and exhibits a slight obliquity. Its 

 location appears to have been in one of the series near the lateral extremity of the 

 upper jaw. There are six transverse ridges, in form more or less semicircular, 

 which occupy nearly the whole of the crown. The space occupied by the marginal 

 corrugations is not large, but the characteristic folds extending from the central 

 portion to the periphery are quite distinct. 



Formation and Locality. — Etage Danien ; Annetorp, District of Malma, 

 Oretorp. 



Ex coll. — Riksmuseum, Stockholm. 



Tooth allied to Diodon. 



Ptychodus mammillaris. 



Ptychodus decurrens. 

 Ptychodus altior. 

 Ptychodus mammillaris. 



Ptychodus mammillaris. 



Ptychodus mammillaris. 



Ptychodus mammillaris. 



Ptychodus decurrens. 



Ptychodus mammillaris. 



Ptychodus mammillaris. 

 Ptychodus mammillaris. 



Ptychodus mammillaris, Agassiz. 

 (PI. XXXVIII., fig. 3.) 



Mantell, G. a., 1822. " Foss. S. Down," p. 231, 



pi. XXXII., figs. 17, 18, 20, 21, 27, 29. 

 Agassiz, L., 1839. " Poiss. Foss.," vol. iii., p. 151, 



pi. XXV. b, figs. 12-20 (? fig. 11). 

 Agassiz, L., 1839. Tom. cit.,T[>. 154, pi. xxv.b, figs. 3, 5. 

 Agassiz, L., 1839. Tom. cit., p. 155, pi. xxv. J, figs. 9, 10. 

 Eeuss, a. E., 1845. " Verstein. bohm. Kreideform," 



pt. i., p. 2, pi. II., figs. 11—13. 

 GiEBEL, C. G., 1848. " Fauna der Vorwelt," vol. i., 



p. 333. 

 Dixon, F., 1850. "Foss. Sussex," p. 361, pi. xxx., 



fig. 6 ; pi. XXXI., fig. 4. 

 Geinitz, H. B., 1850. " Charact. Bohm-Sachsisch. 



Kreidegeb.," 2nd ed., p. 64, pi. xvii., fig. 7. 

 Geinitz, H. B., 1850. Op. cit., p. 64, pi. xvii., 



figs. 8-12. 

 KiPRiJANOFF, v., 1852. "Bull. Soc. Imp. Nat. Moscou," 



vol. XXV., pt. ii., p. 487, pi. xii., fig. 3; pi. xiii., 



fig. 3. 

 PiCTET, F. J., 1854. " Palseont.," 2nd ed., vol. ii., p. 265, 



pi. xxxviii., fig. 27. 

 Fischer, C. E., 1856. " Allgem. deutsch. naturh. Zeit. 



Dresden," N.S., vol. ii., p. 139, pi. ii., fig. 34. 



