COMKON STURGEON. 371 



the body pentagonal, gradually tapering towards 

 the tail, and covered throughout the whole length 

 by five rows of strong, large, bony tubercles, round- 

 ed at the base, radiated from the centre, and termi- 

 nated above by a sharp curved point in a reversed 

 direction : of these five rows of tubercles one is situ- 

 ated on the top of the back, and two on each side the 

 body, the lowermost forming the edges of the abdo- 

 men, which is flat : the whole skin also, except on 

 the belly, is roughened by very small tubercles of 

 similar structure : the head is rather large, sloping 

 on each side, and covered with bony plates ; the 

 snout long and slender, obtuse at the tip, and fur- 

 nished beneath, at some distance from the end, 

 with four long, worm-shaped beards or cirrhi : the 

 mouth is placed immediately beneath the upper 

 part , of the head, and consists of a transverse oval 

 orifice, totally destitute of teeth, but containing a 

 thick and strong tongue, and is bounded above and 

 below by a strong, cartilaginous edge or lip, which 

 it has the power of retracting and closing at plea- 

 sure: the gill- cover, on each side, consists of an 

 oval, radiated plate : the pectoral fins are oval, and 

 middle-sized: the dorsal small, and situated very 

 near the tail; the ventral and anal fins are also 

 small, and placed nearly opposite the dorsal : the 

 tail is lobed or slightly forked, the upper Ipbe being 

 strengthened above by a bony ridge or carina, and 

 extending far beyond the lower : the general colour 

 is cinereous above, with dusky variegations or 

 specks and whitish or yellowish beneath : the tops 

 of the tubercles are also of a similar cast, 



