Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 369 



genus is represented by species still existing. In one of them, Odontaspis ferox^ 

 Agass., all the teeth except those situated most posteriorly, have a high, narrow, 

 pointed crown, on each side of which are two, sometimes three, rounded and 

 acuminate denticles. Both these and the median cone are more or less cylindrical, 

 and usually exhibit a sygmoidal curvature. The teeth of both the upper and 

 lower jaw are similar in form ; on each side of the symphysis there is a small 

 pointed tooth, succeeded by much larger ones, narrow at the base as compared 

 with the height of the crown. In the upper jaw between the second and third 

 large tooth, the fourth and succeeding ones from the symphysis, there are four 

 teeth, very small, about one-third the height of the large front teeth. After these 

 are larger ones, broader at the base, all with acuminate crowns, and diminishing 

 in size backwards. In the lower jaw the intermediate small teeth do not occur, 

 but the teeth gradually diminish in height and size backwards. All are possessed 

 of two lateral denticles on each margin of the teeth. Agassiz* did not consider 

 that the teeth of Odontaspis were separated with sufficient distinctness from 

 Lamna to warrant him in forming a new genus ; but the teeth found fossil which 

 approached the living Odontaspis, he indicated by placing the word in a parenthesis. 



Another genus of the Lamnidse occurs in the chalk of Mount Lebanon, and 

 was described by the writerf as Rhinognathus. It forms one of a very few 

 instances in which the body of a Lamnoid fish with teeth in the natural position 

 have been found fossil. It is distinguished from existing genera by the length of 

 the anal fin. The body is long, and the snout much elongated, and more or less 

 spatulate. The teeth are long and accuminate, with a pair of small lateral 

 denticles in the anterior part of the jaws, broader and shorter behind. The 

 teeth are not readily distinguishable from those of Odontaspis ; and the broader 

 ones are not unlike some of the species of Lamna. Mr. A. Smith WoodwardJ has 

 pointed out that the genei'ic name Rhinognathus was pre-occupied by Fairmaire 

 in 1873, and has suggested Scapanorhynchus in its stead. § 



In addition to the species from Lebanon, Mr. Woodward has included under 

 this genus several species described by authors as Lamna and Odontaspis. 



Dr. H. E. Sauvagejl in 1872 described a number of fish remains from the 

 Cretaceous rocks of Sarthe, and amongst others, species of the genera Oxyrhina, 

 Otodus, Lamna, and Odontaspis. Agreeing with Agassiz in the diagnosis of 



* Poiss. Foss., vol. iii., p. 288. 



f James "W". Davis On the Fossil Fishes of the Chalk of Mt. Lebanon, in Traus. Eoy. Dub. Soc, N.S., 

 1887, part v., vol. iii., p. 480. 



J Catalogue Foss. Fishes in the Brit. Mus., 1889, part i., p. 351. 



§ The inference drawn by Mr. "Woodward that this genus was considered as one of the Spinacidse is 

 incorrect. The omission of a line after the description of the preceding species may have led to the error. 



II Eech. sur les Poiss. Foss. du Terrain Cretace de la Sarthe, in Bibl. Ecole H antes Etudes, vol. v., art. 

 9, p. 20. 



