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



slight vertical grooves from the base upwards on the outer coronal surface, giving 

 it the appearance of a median depression ; laterally the crown exhibits a sigmoidal 

 curvature ; height 0-018 m. ; breadth at base of crown 0-009 m. ; outer coronal 

 surface slightly convex below, flat above ; inner surface equally convex with the 

 outer ; margins thin and sharp. Base of crown concave and receding on the 

 outer ; prominent and overlapping the root on the inner surface ; laterally wide 

 and expanded ; no lateral denticles. Root short, compressed antero-posteriorly 

 like crown ; laterally extending beyond crown, with bluntly-terminating divergent 

 branches; base with comparatively slight concavity. Postero-lateral teeth 

 broader, shorter, and more acutely pointed. 



These teeth are separated from Odontaspis elegans, Ag., by the total absence 

 of lateral denticles, and, though superficially resembling them in form, they are 

 thinner and more compressed. The posterior teeth are broader and shorter, as 

 compared with the anterior ones, than in 0. elegans. The broadest teeth approach 

 Oxyrhina enysii, Davis, a species found in the Senonian formations of Oamaru and 

 Waipara in New Zealand. (" Trans. Roy. Dublin Society," N.S., vol. iv., p. 28, 

 pi. v., figs. 17-20.) 



They appear to be most closely associated with, and to possess the character- 

 istics ascribed by Agassiz to a number of small teeth from the Greensand of 

 Ratisbon (" Poiss. Foss.," vol. iii., p. 284, pi. xxxvi., figs. 49-52). Agassiz was 

 in doubt as to the presence of lateral denticles, because the roots and a portion of 

 the base in the examples at his disposal were broken off. With the specimens 

 from the Swedish Cretaceous rocks this point is made clear ; the base and roots 

 are well preserved, and there are no lateral denticles. Fig. 48 {op. cii.), which 

 Agassiz included in this species, H. E. Sauvage considers to be the lateral denticle 

 of a large tooth of Otodus from the white Chalk of Villavard, which is described 

 as 0. spathda{"' Rech. sur les Poiss. Foss. du terrain Cr^tac^ de la Sarthe," " Bibl. 

 Ecole des Hautes Etudes," vol. v., pp. 23 and 33). The type of 0. zippei, 

 represented in the figures 49—52, and with fig. 48 eliminated, agrees with the 

 examples from Oppmanna, and the latter appear to be naturally included in the 

 species. 



Formation and Locality. — Lower Senonian : Oppmanna, Oretorp. 



Ex coll. — Geological Museum, University of Lund ; Riksmuseum, Stockholm. 



