84 REPORT OF NEW. JERSEY STATE MUSEUM. 
Order CHONDROSTEI. 
The Sturgeons. 
Contains only the family of Sturgeons. 
Family ACIPENSERID/. 
The Sturgeons. 
Body elongate, subcylindrical. Snout produced, depressed and 
subspatulate. Eyes small. Mouth small, inferior, protractile, 
with thickened lips. No teeth. Maxillary distinct from premax- 
illaries. Four barbels in a transverse series on lower side of 
- snout in front of mouth. Nostrils large, double, in front of eye. 
Gills four and an accessory opercular gill. Gill-membranes united 
toisthmus. No branchiostegals. Pseudobranchiz small or obso- 
lete. Air-vessel large, simple, connected with cesophagus. Stom- 
ach without blind sac. Pancreas divided into pyloric appendages. 
Rectum with a spiral valve. Body armed with five rows of bony 
bucklers, each with a median carina terminating in a spine which 
sometimes becomes obsolete with age. A median dorsal series 
and a lateral and abdominal series on each side, latter sometimes 
deciduous, and between these skin rough with small irregular 
plates. Head covered by bony plates joined by sutures. Fin 
rays slender, all articulated and vertical fins with fulcra. Dorsal 
placed posteriorly, anal somewhat behind it and similar. Tail 
heterocercal, lower caudal lobe developed and upper covered with 
rhomboid scales. Pectorals placed low. Ventrals many-rayed 
and behind middle of body. 
Large fishes of the seas and fresh waters of northern countries, 
feeding on small animals and plants sucked in through the tube- 
like mouth. The variation due to age is great and together with 
the individual variation has given rise to many nominal forms. 
In our waters but two species referable to the genus Acipenser. 
