428 Mr. Davis on a 



alveolar surface to the base, which is O'Oio m. in diameter ; 

 in the opposite direction the diameter is equal to half the 

 height. The basal, or under surface of the jaw is exhibited, 

 and from its peculiar curvature appears to indicate that 

 the part preserved is the anterior portion of the right ramus 

 of the lower jaw, with the symphisial extremity slightly 

 exposed. The surface of the bone is smooth, with the 

 exception of a few moderately large punctures. Attached 

 to the upper surface of the jaw is a small tooth, probably 

 intermediate between the large lamiary tooth, which has 

 a length of 0*004 m. It has similar characters to the 

 larger ones, and its surface is distinctly striated. In the 

 matrix adjoining there is the impression of a second 

 similar small tooth. 



No. 5. Large bone exhibiting internal structure. The 

 external surface, where exposed, is of the same character 

 as the exposed part of the jaw in No. 4, and in other 

 respects it may be possible that this bone is a larger jaw 

 of the same species, but there are no distinct indications 

 of teeth. The part preserved is about 005 m. in length, 

 and 0'022 m. in breath. 



No. 6. Dermal bones, probably from the cranium. 



No. 7 is a bone similar to No. 5, broken into four 

 separate pieces, but exhibiting no well-defined character. 



Nos. 8, 9, and 10 are apparently more or less frag- 

 mentary remains of small ribs, which, being found associated 

 in the same bed with the specimens already named, may 

 naturally be inferred to have belonged to the same species, 

 if not to the same fish. The best preserved specimen 

 (No. 8) is 0*03 m. in length, and is 0'002 m. in diameter ; 

 both ends are broken off. The portion preserved exhibits 

 a gentle curvature. 



No. II is a specimen of a rib which is probably 

 complete, and is o'o6 m. in length, and is about the same 

 diameter as the others. It has a bold curvature, the distal 



