FISH OF ONTARIO. 15 



or two series of large teeth, besides which on the jaws vomer and palatines 

 are a series of small, close-set, rasp-like teeth. Large teeth of the jaws 

 conical in form, pointed and striate, placed at right angles to the jaw. 

 Pharyngeals with rasp-like teeth. Tongue toothless, short, broad, emar- 

 ginate, free at tip. External bones of skull very hard and rugose. Eyes 

 small. Nostrils near the end of the upper jaw. An accessory gill on the 

 inner side of the opercle. Pseudobranchias present. No spiracles. Gills, 

 four, a slit behind the fourth. Branchiostegals, three. Gill membranes 

 somewhat connected, free from the isthmus. Gill rakers very short. Air 

 bladder cellular, lung-like, somewhat functional. Fins with fulcra ; dorsal 

 fin short, rather high, posterior, nearly opposite the anal, which is similar 

 in form; tail heterocercal, in the young produced as a filament beyond the 

 caudal fin; caudal convex; ventrals nearly midway between pectorals and 

 anal ; pectorals and ventrals moderate, few rayed. Stomach not caecal ; 

 pyloric appendages numerous. Spiral valve of intestines rudimentary. 

 Fresh water fishes of sluggish habits, but voracious and destructive to 

 smaller fishes. The flesh is tough and rank, useless as food. 



These fishes are of much interest from their relationship to extinct 

 ganoid genera, many of which are placed in this family. 



Genus LEPISOSTEUS. (Gar Pikes.) 



Upper jaw with an outer series of small, sharp, even teeth, 

 then a series of large teeth, some of the anterior row being usually 

 movable; next comes a series of fine teeth, in one row in front, 

 becoming a band behind. In some species the inner row of these 

 teeth contains larger ones ; next the vomerine teeth, also in a long band, 

 and posteriorly a palatine band. These bands on the roof of the mouth are 

 trequently somewhat confluent or irregulai. Tn young specimens some of 

 the palatine teeth are often enlarged, these sometimes forming regular 

 series. Lower jaw with an outer series of small teeth, next a series of large 

 teeth, next again a broad band of fine teeth on each side. Each of the 

 large teeth fitting into a depression in the opposite jaw. 



Subgenus LEPISOSTEUS. 



(5) Gar-fish. Gar Pike. Bill-fish. 



(Ltpisosteus osseus.) 



Body elongate, subcylindric. The jaws greatly produced, the upper 

 being the longer. Teeth in the jaws rather fine, sharp and stiff; a single 

 inner row of large teeth, and an outer row of small teeth on each side. 

 The snout is more than twice as long as the rest of the head. 



D., 7 to 8; A., 9; v., 6; P., 10. Scales, 62 to 65. 



