In the “Catalogue of Fossil Fishes in the British Museum“ (pt. i. 1889, p. 76, pl. iii. fig. 1), the imperfect rostrum of a Selachian fish from the Upper Cretaceous of Mount Lebanon was described under the new generic and specific name of Sclerorhynchm atavus. Presenting some resemblances to the rostrum both of the typical saw-fish (Prislis) and of PristiopJtorus, hesitation was expressed in determining the systematic position of the genus to which the fossil pertained; but from the apparently complex nature of the rostral cartilages and the absence of extended prepalatines, it was deemed advisable to place the fish provisionally in the family of Pristidæ.