BONY-PIKE. 507 



quadrangular ganoid type, and the branchiostegal rays having no gular plate 

 in advance of them. 



Existing Family. As a famil y' the bony-pikes, of which the common species 



(Lepidosteus osteus) is shown in our illustration, are distinguished 

 from all other fish by having the bodies of the vertebrae convex in front and con- 

 cave behind, instead of having both surfaces cupped. The fins are furnished with 

 fulcra, the dorsal and anal consisting of soft rays only, and placed far back, and 

 near the caudal, which is of the abbreviated heterocercal type ; while the trunk is 

 much longer than the abdominal portion of the vertebral column, and the bran- 

 chiostegal rays are comparatively few, and have not an enamelled outer surface. 

 In form, the body of the bony-pikes is elongate and subcylindrical ; the long- 

 muzzle is either spatulate or beak-shaped ; the cleft of the mouth wide ; and both 



BONY-PIKE ( nat. size). 



the palate and jaws are armed with bands of rasp-like teeth, and also with larger 

 conical ones. There are four gills and three branchiostegal rays on each side ; and 

 the air-bladder is cellular. Bony-pike, of which there are three existing species, 

 are now confined to North and Central America and Cuba ; but they are repre- 

 sented in the European Eocene, and b}^ allied extinct genera in the Eocene and 

 Miocene strata of the United States, one of these also occurring in the French 

 Eocene. The existing forms grow to a length of 6 feet, and are carnivorous, feed- 

 ing upon smaller fishes. They are often known by the name of gar-pike, although, 

 as mentioned on p. 400, that title is best restricted to a totally different group. 



The extinct Jurassic spear-beaks (Aspidorhynchus) constitute a 

 second family (Aspidorhynchidoe), distinguished by the normal 

 structure of the vertebrae, the homocercal tail, and the production of the upper 

 jaw ; the general form of the body and the arrangement of the fins being very 

 similar to that obtaining in the bony-pike. 



Spear-Beaks. 



