TELE OS TOMES 



parenthetically (Fig. 165 A) be inserted ; it is of especial 

 interest as suggesting an approximation of the type of the 

 modern sturgeon to that of the Palaeoniscoid ; its snout is 

 shorter than in Acipenser ; its jaws larger, and apparently 

 less protrusible ; its dermal plates of the head region, 

 including the branchiostegals, are clearly of the ancient 

 pattern, and the fins, fin supports, and vertebral characters, 



Fig. 166. The shovel-nose sturgeon, Scaphirhynchus platyrhynchus (Raf.), 

 Gill. X \. Mississippi basin. (After GOODE in U. S. F. C.) 



together with the general small size of the fish, suggest 

 intermediate conditions. 



Of the remaining sturgeons, the shovel-nose, ScapJii- 

 rhynchus (Fig. 166), of the Mississippi and of Central Asia, 

 seems to possess the closest relations to Acipenser; 

 although it is apparently a more modified form, on account 

 of its elongate body shape and flattened snout, it still 

 retains many interesting and archaic features. Among 



Fig. i66A. Psephurus gladius, Gun. x \. Rivers of China. (After GUNTHER.) 



these it includes the most complete dermal armouring of 

 recent forms, its hinder body region being entirely encased. 

 Psephiirus (Fig. i66A), of the Chinese rivers, and Poly- 

 odon, or Spatularia (Fig. 166 B\ of the Mississippi, are 

 the other forms of living sturgeons. Their greatly elon- 

 gate snouts, giving them the popular names of Spoonbills, 

 Paddle-fish, Spear-fish, are among the most remarkable 



