PLATE II. 



IsisTius BRASiLiENsis Q. G. Page 34. 



Fig. 1. Outlines of the head as seen from above. 



Fig. 2. Outlines of the head as seen from below. 



Fig. 3. Skull as viewed from above. 



Fig. 4. Skull as it appears from the side. 



Fig. 5. Skull from the inside, in a vertical longitudinal section. 



Fig. G. Branchial cartilages of the right side, seen from below, showing the basihyal, ceratohyal, 

 ceratobrancliials and extraviscerals. 



Fig. 7. Brancliial cartilages of the right side, seen from above, showing the pharj-ngobraucliials, 

 epibranchials and branchial raj's. 



Fig. 8. Teeth from the upper jaw, four times life size. 



Fig. 0. Teeth from the lower jaw, four times life size. 



