546 J. H. Cooke — On Stereodon Melitensis. 



determination even of fragments. The feebly marked rugae are 

 broad and rounded, and towards the superior margin of the scales, 

 more particularly on the caudal pedicle, they exhibit a tendency 

 towards arrangement in a series of short, parallel, vertical folds. 



IV. PSEUDOTRIONTX FROM THE BraOKLESHAM BedS. 



By A. Smith Woodward, F.G.S., F.Z.S. 



THE extinct genus of Chelydroid Chelonians to which M. Louis 

 DoUo gave the name of Fseudotrionyx,^ has already been re- 

 corded from the London Clay of Sheppey, by Messrs. Lydekker and 

 Boulenger.^ It is somewhat remarkable, however, that until the 

 recent acquisition by the British Museum of the collection of Mr. 

 J. B. Ogle, no certain evidence had been observed of the occurrence 

 of the genus in the Bracklesham Beds — the English equivalent of 

 the Bruxellian Series which yielded the Belgian Psseudotrionyx 

 Delheidi. 



This evidence is still very small, but appears nevertheless conclu- 

 sive. It consists of one of the middle marginal bones, well preserved, 

 and showing the pit for the reception of the extremity of the rib. 

 The bone measures 0-05 m. in length, 0-042 in the maximum width 

 of the upper face, 0*03 in that of the lower face, and 0-018 in the 

 maximum thickness of the angulation. Both the upper and lower 

 faces of the bone are covered with the characteristic coarse, but 

 faintly-marked pitted, ornament ; and the angulation of one extremity 

 measures about 90°, while that of the other is slightly greater. 



The fossil thus described agrees so closely in its proportions and 

 sculpturing with the type-species P. Delheidi that, in the absence of 

 further material, it may be assigned to this form. 



Y. — Notes on Stereodon Melitensis, Owen. 

 By John H. Cooke, F.G.S., etc. 



IN the year 1865 portions of the upper and lower jaws of a 

 large extinct fish that had been found imbedded in the Globi- 

 gerina Limestone^ of Malta were submitted by Dr. Leith Adams to 

 Professor Owen for identification. Adams had considered them as 

 being the remains of a crocodilian ; but in a paper that appeared 

 in the Geological Magazine for April, 1865,* Owen pronounced 

 them to be the remains of a large extinct fish that belonged to " the 

 cycloid order, and having saui-oid dentition," and he proposed that 

 "this fine addition to Miocene Tertiary fishes" should be known by 

 the name of Stereodon Melitensis. 



1 L. Dollo, "Premiere Note sur les Cheloniens dii Bruxellian (Eocene Moyen) 

 de la Belgique," Bull. Mus. Eoy. d'Hist. Nat. Belg. vol. iv. (1886), pp. 75-96, 

 pis. i. ii 



2 R. Lydekker and G. A. Bnulenger, Geol. Mag. [3] Vol. IV. (1887) p. 274. 

 ^ Bed IV. I'lie "freestone" of Spratt and Adams. 



* " Stereodon Melitensis," Owen, Geol. Mag. April, 1865. 



