ACTINOPTERI. 149 



Family LEPISOSTEID^E. 

 THE GAR PIKES. 



Body elongate, subcylindrical. Jaws mostly elongate, spatu- 

 late or beak-like, upper projecting beyond lower. Eyes small. 

 Premaxillary forms most of upper jaw edge. Maxillary trans- 

 versely divided in several pieces. Lower jaw composed of as 

 many pieces as in reptiles, coronoid present. Both jaws with outer 

 series of small teeth followed by one or two series of large teeth, 

 besides series of small close-set rasp-like teeth on jaws, vomer 

 and palatines. Large jaw teeth of conic form, pointed, striate, 

 placed at right angles to jaw. These teeth resting in rather deep 

 furrow protected on outside by raised border of jaw, on inside 

 by similar ridge, pierced in center by foramen communicating 

 with maxillary canal through which nerves and blood-vessels 

 enter pulp cavity of tooth. Forms of folded dentine layers within 

 teeth peculiar. Pharyngeal teeth rasp-like. Tongue tooth- 

 less, short, broad, emarginate, set free at tip. Nostrils close to 

 upper jaw tip. Gill-membranes somewhat connected, free from 

 isthmus. Gills 4, slit after fourth. Gill-rakers very short. 

 Pseudobranchiae present. Branchiostegals 3. Accessory gill on 

 inner side of opercle. Air-vessel cellular, lung-like, somewhat 

 functional. Stomach not ccecal. Pyloric appendages numerous. 

 Intestinal spiral valve rudimentary. Body covered with hard 

 rhombic ganoid scales or plates, imbricated in oblique series ex- 

 tending downward and backward. External skull bones very 

 hard, rugose. Fins with fulcra. Dorsal fin short, rather high, 

 posterior, nearly opposite similar anal. Tail heteroeercal, in 

 young produced as filament beyond caudal. Caudal convex. 

 Pectorals and ventrals moderate, few rayed, latter nearly mid- 

 way between former and anal. 



The existing forms are large fishes, chiefly of the fresh waters 

 of Xorth America, referred to one or two genera. Several generic 

 names have been applied to the fragmentary fossil forms, which 

 are here included under Lepisosteus. It seems likely that the 

 existing forms are divisable into two genera, of which Cyiin- 

 drosteus may also be maintained. 



