CARTILAGINOUS PISHES. 517 
quen ting the Volga and the Danube. The enormous consumption of 
caviare in Russia leads to a deadly pursuit of the common sturgeon in 
all the great European rivers, and this species is in a fair way of dis- 
appearing altogether. 
The Common Sturgeon, Acipemer sturio (Fig. 355), abounds in the 
horth Sea and the Mediterranean, and occasionally it appears in the 
Thames, the Ehine, the Seine, the Loire, and the Gironde. It is 
usually about two yards to seven feet long, but has been known to 
attain tbe length of ten or twelve feet. Its general colour is yellow 
Fig* 355. The Common Sturgeon (Aclpenser sturio). 
^ith a white belly. It is rendered remarkable by the number and form 
1 ,|f ' the osseous plates or scales, which cover the body like so many 
bucklers. Upon tbe back and belly are no less than twelve to fifteen 
°1 these rough bony plates, relieved by projections, which are pointed in 
the young, and soften down with age. On each side is a row of thirty 
to thirty-five of these triangular plates, separated from each other by 
considerable intervals. The head is broad at the base, gradually con- 
tracting towards the point, and terminating in a conical muzzle. The 
'ttouth is large and considerably behind the extremity of the muzzle. 
an d its jaws, in place of teeth, are furnished with cartilages. Between 
