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



II.— CLASSIFIED DESCRIPTION OF THE FOSSIL FISH. 



Class.— PISCES. 

 Sub-Class.— ELASMOBRANCHII. 



Order. — S elachii. 



Sub-Order. — Tectospondyli. 



Family.— MYLIOB AT ID ^. 



Genus. Myliobatis. Cuvier. " Rfegne Animal," vol. ii., p. 137. 1817. 



Head free from the disk ; so-called cephalic fin single. Teeth large, flat, 

 hexangular, tesselated, arranged in seven antero-posterior series. The dentition 

 of the upper jaw strongly arched antero-posteriorly, that of the lower jaw quite 

 flat. Dental crown smooth, or slightly striated ; attached surface of root 

 longitudinally rigid and grooved. Excej^t in very young individuals, in which 

 the teeth are all approximately of equal size, the median row is relatively very 

 broad, while the teeth of the three lateral series on each side are rarely broader 

 than long. Tail with a dorsal fin near its root, generally with a posteriorly- 

 situated barbed spine. 



Myliohatis, sp. ? 



Fragments of the teeth of this genus occur in the collection of the University 

 of Lund. The coronal surface is smooth, and presents a somewhat reticulated 

 appearance, due to the attrition of the upper extremities of the descending 

 nutritive canals. The root, composed of coarse lamellae, is smaller than the 

 crown, and is separated from it by a concave depression of the iDosterior surface, 

 the root projecting beyond the crown ; on the anterior surface the reverse happens, 

 the surface of the crown extending beyond the root. 



The specimens are fragmentary, and of too indefinite a character to determine 

 the species. 



Ex coll. — Geological collection, University of Lund. 



