PR18TID>E. 
73 
Family PRISTIDiE. 
Body scarcely depressed; pectoral fins of moderate size, not 
extending to the snout; gill-openings ventral. Snout produced 
into a long flat lamina, armed with a series of strong teeth on each 
edge ; prcpalatine cartilages inconspicuous. 
Genus PRISTIS, Latham. 
[Trans. Linn. Soc. vol. ii. 1794, p. 276.] 
Syn. Myriosteon, J. E. Gray, Proc. Zool. Soc. 1804, p. 164. 
Teeth of rostrum firmly implanted in sockets of calcified cartilage : 
no tentacles. Teeth in jaws minute, ohtuse. Spiracles wide, behind 
the eyes. Dorsal fins without spine, the first opposite or close to 
the base of the pelvics ; caudal fin large. 
The known fossil remains of this genus being only detached 
vertebrse, teeth, and fragments of the rostrum, it is impossible to 
determine the number and characters of the extinct species repre- 
sented in collections. The specific names are thus aU provisional. 
One of the hoUow cartilaginous rods of the rostrum was described 
by Gray as Myriosteon. 
Pristis bisulcatus, Agassiz. 
1843. Pristis bisidcatm, L. Agassiz, Poiss. Foss. vol. iii. p, 382*, 
pi. 41. 
1833-43. Pristis hastingsicB, L. Agassiz, tom. cit. p. 382* (name only). 
18.50. Pristis, F. Dixon, Foss. Suss. pi. xii. figs. 0, 7. 
1883. Pristis (?) bisulcatus, W. Dames, Sitzungsb. math.-phys. Cl. 
Akad. Wiss. Berlin, pt. i. p. 139. 
Type. Portion of rostrum, wanting teeth ; British Museum. 
As already pointed out by Dames, tho character to which Agassiz’s 
specific name refers is common to aU known Saw-fishes. The 
original specimen was almost certainly obtained from the same 
stratum as the majority of tho detached rostral teeth resembling 
that forming the tj-pe of P. Jiastinysia ; and there is every gradation 
from tho small size of the latter to the largo.st that would be re- 
quired for the snout indicated by the fossil cartUage. The rostral 
teeth are grooved posteriorly, and not bent. 
Form, dr Loc. tipper Eocene: Barton Cliff, Hants. Middle 
Eocene : Bracklesham Bay, Sussex. 
