J)^yig — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 379 



Ptychodus mammillaris. Roemee, F., 1870. " Geol. von Oberschlesien," p. 324, 



pi. XXXVI., fig. 8. 

 Ptychodus mammillaris. Sauvage, H. E., 1872. " Biblioth. Ecole Haute Etudes," 



vol. v., art. 9, p. 16, pi. ii., figs. 86-89. 

 Ptychodus mammillaris. Geinitz, H. B., 1875. " Pal^ontogr.," vol. xx., pt. i., 



p. 297, pi. Lxiv, fig. 26; pt. ii., p. 213, pi. xl., 



figs. 23-29. 

 Ptychodus mammillaris. Feitsch, A., 1878. " Reptil. und Fische bohm Kreide- 



form," J). 14, woodcut fig. 33. 

 Ptychodus mammillaris. St. Zaeecznego, 1878. " Sprawozdanie Komisyi Fizy- 



jograf. Galicyi," vol. xii., p. 201, pi. viii., fig. 9. 

 Ptychodus mammillaris. Quenstedt, F. A., 1885. " Handb. Petrefakt," 3rd 



ed., p. 282, pi. XXI., figs. 61, 62. 

 Ptychodus mammillaris. Woodwaed, A. S., 1889. " Cafcal. Foss. Fishes in Brit. 



Museum," pt. i., p. 133. 



The occmrence of Ptychodus mammillaris is not common. The specimen 

 figured is from the white chalk of Annetorp. It is very high in the crown, with 

 ten or twelve transverse ridges extending across the somewhat narrow sm-face. 

 The diameter of the base is 0-015 m., equal to the height of the crown. Below the 

 coronal surface the sides are depressed, and covered with more or less concentric 

 granulated strise ; still lower the sides again expand, and the base is prominent, 

 and covered with fine vertical striations. 



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



Ex coll. — Riksmuseum, Stockholm. 



Sub-Order. — A st e e o s p o n d y l i. 



Family.— NO TIDANID^. 



Genus. Notidanus. Cuviee. 



Body moderately elongated ; one dorsal fin opposite to the space between the 

 ventral and anal fins ; caudal fin large, without pit at the root ; mouth inferior ; 

 gill-openings — six or seven — without flaps of skin ; spiracles small, on the side of 

 the neck. Notochord persistent. Principal teeth consisting of a series of com- 

 pressed cusps, fixed upon a long base, the anterior cusp larger than the others, 

 with or without small denticles at its base in front. Anterior teeth of the upper 

 jaw clustered, awl-shaped ; a median symphysial series in the lower jaw. 

 Principal teeth of the upper jaw less laterally elongated, with fewer cusps than 

 those of the lower jaw. 



TRANS. SOr. DTJB. SOC, N.S., VOL. IT., PAKT VI. 3 I 



