PEISTIS FAJUMENSIS. 317 



Subclass ELASMOBRANCHII. 



Order SELACHII. 



Family PRISTID.E. 



Genus PRISTIS, Latham. 

 [Trans. Linn. Soc. vol. ii. 1794, p. 276.] 



Rostral teeth firmly implanted in sockets, forming square notches on the sides of 

 the saw-like rostrum. 



Pristis fajumensis, Stromer. 



1897. Propristis scJiweinfurtJii, F. Priem, Bull. Soc. Geol. France, [3] vol. xxv. p. 228 {errore). 

 1905. Pristis fajumensis, Ernst Stromer, Beitr. Pal. u. Geol. Oesterreich-Ungarns u. d. Orients, 

 vol. xviii. p. 49, pi. vi. figs. 1-3. 



Type Specimen. — Portions of a rostrum ; Palaeontological Museum, Munich. 

 This species is a true Pristis, the teeth being set in calcified sockets, forming 

 quadrate notches, about 23 in number, on the sides of the rostrum. 



Form. & Log. — Qasr-el-Sagha beds (Middle Eocene) : north of Birket-el-Qurun. 



C. 10303. A nearly complete rostrum (text-fig. 98). In this specimen there are 22-23 notches for 

 teeth on either side ; posteriorly these are not opposite one another on the two sides,' 



Text-fig. 98. 



u 

 x4 



Eostrum of Pristis fajumensis. ^ nat. size 



but to some extent alternate ; at the extreme anterior end the notches are opposite 

 to one another. The dimensions (in centimetres) o£ this specimen are : — 



Extreme length 87 



Greatest width of base of rostrum 8-2 



Width of tip of rostrum 1-3 



Distance between two posterior teeth 4-1 



„ „ anterior teeth 1-5 



C. 10204. Portion o£ a rostrum, with notches for teeth much more closely set than last. Possibly 

 another species. 



