EXPLANATION OF PLATE LXXI. 



Figure 



1. Pleuracanthus (Diplodus) Icuvissimus, Agass., exhibiting the posterior part of the bead, 



together with spinous bones of the hsemal or neural arches, and inter-spinous bones. 

 (Reduced to half diameter.) 



a. Lower jaw. 



b. h. Cranial plates dissociated. 



c. Vertebral spines (? neural), with enlarged base. 



d. Inter-spinous rays. ' 



e. Surapophysial ray. 

 t. Teeth. 



2. Inter-spinous ray. Natural size. 

 3. 



4. Surapophysial ray. ,, 



5. Teeth. Enlarged. 



Formation aud Locality. — Low Main Coal Seam, Newsham, Northumberland. 

 Ex coll. — William Dinning, Newcastle. 



[14] 



