106 



PISCES. 



Genus OXYRHINA, Agassiz. 



OXYEHINA HASTALIS, AGASSIZ. 



{Including O. XIPHODON.) 



Plate IX., Figs. 15a, b. 



Among the shark's teeth from the Suffolk Crag, a number may 

 be found of a broadly triangular and flattened form which, although 

 retaining the cutting edge almost unworn, show no signs of any 

 serration like that found in Carcharadon, and are destitute of 

 lateral denticles. Such teeth are referred to the genus Oxyrhina 

 and have usually been called O. xiphodon, Agassiz (Poiss. Foss. 

 Vol. III., p. 278) ; other of these teeth have narrower but thicker 

 crowns and agree with those named O. hastalis by Agassiz 

 {loc. cit., p. 277). 



A large series of teeth found associated in the Pliocene of 

 Tuscany, and described by E.. Lawley (Studi Oomp. Pesci, &c., 

 1881, P. 93) under the name of O. Agansizi, show the wide 

 variation which may occur in the teeth of one pair of jaws, and 

 has led Mr. Smith Woodward (Cat. Foss. Fishes, B. M., p. 385, 

 1889) to associate under the name of O. hastalis, several species, 

 including the three above mentioned. The forms figured by 

 Lawley as O. Agassizi differ somewhat from those found in the 

 Crag with which I am familiar, 



Messrs. R.and A. Bell (Proc.Geol. Assoc, Vol. ii.,p.202) recorded 

 O. xiphodon from the true Coralline Crag of Suffolk and there 

 are three specimens referred to the present species in the British 

 Museum from the same horizon ; but by far the larger number 

 of English specimens are from the Nodule-bed below the Bed 

 Crag of Suffolk. 



This species is also recorded in the British Museum Catalogue 

 from Pliocene beds at Antwerp, Montpellier, and Tuscany ; also 

 from Miocene beds in Belgium, France, Spain, Portugal, Switzer- 

 land, Wiirtemberg, Malta, Italy, Sicily, Corsica, and possibly 

 Melbourne. It has .also been found in the Oamaru system. New 

 Zealand ; in Tertiary beds in the Canary and Cape de Verde Isles ; 

 and in Miocene and Lower Tertiary beds in North America. 



Genus OSONTASFIS, Agassiz. 

 (LAMNA, Agassiz et auctorum.) 



Allusion has already been made (p. 105) to the revision which 

 has necessitated the removal of most of the species of Lamna to 

 Odontaspis and the use of the name Lamna for all those species 

 which have been called Otodus ; attention is again directed to this 

 to prevent any misunderstanding as to the forms here noticed. 



Agiissiz recognised among the English Crag fossils Odontaspis 

 {Lamna) elegans, contortidens, and Hopei (Poiss. Foss., Vol. III., 



