Fisr. 
2 . 
PLATE IX. 
Hybodus medius, Agassiz ; remains of the head and denti¬ 
tion, left lateral aspect, two thirds nat. size. L. Lias ; 
Lyme Regis, c.s. Cephalic spines, md. Left ramus of 
mandible, ptq. Left pterygo-quadrate, obscured by 
shagreen, i.-viii. Successive dental series of the lower 
jaw". [41103.] 
Ditto; tooth with cleft summit, lateral aspect.—Ibid. 
[38881.] 
Pa»e 
3. Ditto ; tooth divided near one extremity, lateral aspect.— 
Ibid. [P. 2794.] 
265 
265 
266 
