322 CLASSIFICATION OF FISHES^ ETC. 



suming a lengthened^ heart-shaped form ; the snout 

 imuch prolonged ; tail thick^ as in ordinary sharks ; 

 teeth tesselated ; hody smooth ; mouth beneath. 

 R. laevis. Russell, pi. 10. 



BJiina Schn. General structure of Rhinohates, but 

 with a short, broad, and rounded muzzle ; connected 

 either to the Torpedinse or to the Trigoninge } 

 R. cyclostomus. Bl. Sch. 72. 



Family 3. PRIONm^. Spoon Fish. 



Muzzle excessively prolonged into a flat, lanceolate 

 plate ; operculum very large, with the branchial opening 

 very wide, and formed as in ordinary fishes. 



PoLYODON Lac. Teeth very smaU, sharp, curved, and 

 serrated ; mouth beneath ; dorsal fin single ; caudal 

 regular, lunate. 

 P. reticulatus Sw. vol. I. p. 122. fig. 7. Lac. i. pi. 12. f. 3. 



Family 4. STURIONIDjE. Sturgeons. 



Body covered with large osseous plates or tubercles^ 

 which form carinated and spinous lateral lines * on the 

 sides of the body, as weU as on the back and belly; 

 mouth placed beneath ; the bony jaws performing the 

 ofiice of teeth. 



AciPExsER Linn. Muzzle prolonged and obtuse; mouth 

 furnished with cirri ; caudal fin lunate ; the upper 

 lobe longest. 



A. Sturio Lin7i. (Vol. 1. p. 123. fig. 8.) 



Family 5. CHIMARID^. 

 Snout abruptly obtuse ; tail long, attenuated, and pointed. 

 Chimera Lin. Profile vertical ; muzzle conical, behind 



* Hence we find that numerous genera, intended to represent this type, 

 have the lateral line elevated or armed with spines : the LoricarincB, the 

 Balistida:, the TriglidiP, all the horse mackerel, and others which will 

 occur to the ichthyologist, are striking examples of this representation. 



