1899] Prince— Paddle-Nosed Sturgeon in Ontario. 155 



survive, and that the young- proereny find their changed environ- 

 ment so unfavorable that most of them perish, hence their rarity. 

 It is with a pathetic interest that the naturalist examines a 

 fresh specimen of a Canadian Polyodon, when the rare opportunity 

 occurs. Its uncouth and indeed grotesque form is largely due to 

 the exaggerated length of the snout which is as long and flat as a 

 canoe paddle. It is said to enable the fish to grub amongst 

 sand and mud and to dislodge small crustaceans, and possibly 

 mollusca, which are supposed to constitute its food. The organ 

 is an enormous and cumbersome one tor so simple a purpose, 

 and it is possible that this lengthy nose or rostrum has 

 other uses. It is, of course, a far more formidable ' 

 organ than the snout of the shovel-nosed sturgeon 

 {ScuphirhyncJms). It recalls the powerful weapon of the 

 Saw-fish [Pristis) and the Sword-fish [Xtphias], and differs most 

 markedly from all its Ganoid congeners in its general external 

 form. Of course the Sword-fish is a shark, and the Saw-fish is a 

 Teleostean allied to the Mackerels [Scomberi'doe), both equally dis- 

 tantly separated from Polyodon, yet there is a striking resemblance 

 in the flat, elongated, blade-like snout of all three. The anatom- 

 ist finds, however, that these externally similar structures are very 

 diff'erently formed, and bear no resemblance to each other when 

 their osteology is examined. Thus in Pristis the mesethmoid rod 

 which, in such a fish as the haddock, projects from the frontal- 

 bone, covering the tore part of the head, is prolonged and flatten- 

 ed, and provided along its lateral edges with twenty or thirty 

 strongs teeth. On the- other hand, in Xiphias, the Sword-fish, the 

 double vomer, which underlies the mesethmoid and roofs over the 

 mouth anteriorly, grows forward, along with the two premaxillary 

 or upper-jaw bones, and the three form the toothed flat beak which 

 is often thirty inches in length. It is the palato-quadrate cartila- 

 ges in Polyodon which are lengthened and shielded by bony maxll- 

 liary plates which form the long spathulte beak in front of the head 

 in this species. I was struck by the massive rotundity and verti 

 cal depth of the body in the Paddle-nosed Sturgeon under consid- 

 eration. The protruding beak occupied fully one-third of the total 

 length of the fish. Its eyes, small, dull, and in life no doubt ex- 

 pressionless like those oi the common Sturgeon, were low down and 



