668 GEOLOGICAL SUEVEY OF NEW JERSEY. 



SuB-Cx,A.ss GANOIDSX. 



Fishes having many structural characters similar to the Elasmo- 

 branchs, but with bony plates in skin instead of scales. 



Section GHONDROSTEI. 



Order GLANIOSTOMI. 

 Family AGIPENSERIDiE. 



Sturgeons. 



Body nearly cylindrical, armed with five rows of bony bucklers, 

 each terminating in a spine ; moUth small, without teeth, but with 

 barbels ; eyes small ; gills four besides the opercular gill ; no bran- 

 chiostegals; head covered by bony plates united by sutures; tail 

 heterocercal. 



AOIPBNSBR, L. 



A. sturio, var. oxyrhynohus, Mitch. American Sturgeon. 



Snout conical, sharp, depressed; a small spiracle over eye; 

 mouth inferior; barbels between mouth and snout; plates on 

 sides of tail ; not so many lateral plates (twenty-seven to twenty- 

 nine) as in European sturio. Ascend rivers of Atlantic coast in 

 spring to spawn. 



" This is the more common of the two species of sturgeon met 

 with in the Delaware River. They were formerly much more 

 abundant than at present, and it would seem as though they then 

 were generally of much greater dimensions. They are taken in 

 the Delaware as far up as Port Jervis, N. Y." 



A. brevirostrie, Le S. Short-nosed Sturgeon. 



Snout one-fourth length of head; bony plates smaller and 

 further apart. 



