PADDLE FISH ; SPOON-BILL. 765 



"The remarkably developed glU-rakers of this species thus receive their explanation. 

 These are very numerous and fine, arranged in a double row on each gill arch, and are 

 twice as long as the filaments of the gill. By their interlacing they form a strainer 

 scarcely less effective than the fringes of the baleen plates of the whale, and probably 

 allow the passage of the fine silt of the river bed when this is thrown into the water by 

 the shovel of the fish, but arrest everything as large as a Cyclops. The fish is said by the 

 fishermen to plow up the mud in feeding with its spatula-like snout, and then to swim 

 slowly backward through the muddy water. Its mouth, it may be noticed, is very large, 

 even for a fish. 



" It is possible that this wholesale destruction of entomostraca may affect the food 

 supply of other and more valuable fishes, especially of the very young of the predaceoue 

 species. We cannot yet say, however, where the stress of the struggle comes in the life 

 of any given species, and consequently are unable either to relieve or heighten it at 

 will, or to perceive the full effect of the forces already at work. Fuller knowledge 

 must precede any but the most cautious and conservative recommendations." 



Synonymy. — This species was first described by Lacepede, under the 

 generic name of Polyodon, in reference to the very numerous teeth in the 

 jaws and palate, which character was considered to distinguish the genus 

 from its relatives, the Sharks and the Sturgeons. Lacepede's description, 

 which is a very minute and excellent one, was made up from numerous 

 young specimens preserved in the French Museum under the name of 

 " Chien de mer feuille". The original locality of these specimens was 

 unknown, as Lacepide remarks, " Nous ne pouvons cependant rien con- 

 jecturer relativement ^ ses habitudes; sur lesquelles nous navons regu 

 aucun renseignement, non plus que sur les mers qu'elle habite ; tout ce 

 que nous pouvons dire, c'est que, par une suite de la conformation de ce 

 Polyodon, elles doivent, pour ainsi dire tenir le milieu entre celles des 

 squales et celles des acipensires." 



A few years later, this fish was again described under the name Spain- 

 laria reticulata Shaw, and this name has been, of late years, occasionally 

 employed by writers in spite of the unquestionable priority of Polyodon 

 folium, on the ground of the inappropriateness of the latter name, the 

 adult fish being often without teeth. There is, however, no good ground 

 for setting aside Polyodon, even if Spatularia seems a more pleasing name. 

 The fish does have many teeth, even if they ultimately fall out, and 

 Polyodon it must remain. 



Still later, old specimens received the name of Platirostra edentula, they 

 being considered to form a genus distinct from Polyodon, on account of 

 their toothle3sness, and of certain alleged differences in form. The 

 identity of Platirostra with Polyodon remained undiscovered until com- 

 paratively recently. 



Laa-tly comes the name Hanirodra spatitla, apparently given with full 



