252 GREAT LAMPREY. 



Mursenae : it arriv^es at a considerable size, and fa 

 the length of more than three feet ; the generality 

 of the British specimens however are of inferior 

 magnitude : the usual colour of the Lamprey is a 

 dull brownish olive, clouded with yellowish white 

 variegations : the back, as in most fishes, is darker 

 than the other parts, and the abdomen paler : the 

 fins are tinged with dull orange, and the tail with 

 blue : the eyes are rather small : the mouth large, 

 oval, situated beneath, deeply concave, and lined or 

 paved as it were with several circular rows of sharp, 

 triangular orange-coloured teeth : the tongue, which 

 is short and creseent-shaped, is also furnished with a 

 row of very small teeth round its edge : on the top 

 of the head is a small orifice or spout-hole, through 

 which is discharged the superfluous water taken in 

 at the mouth and gills : near each eye are two 

 rows of much smaller foramina, one row consisting 

 of five, and the other of six : these are supposed to 

 be the oriiices of the glands which secrete the viscid 

 moisture necessary for lubricating the skin : on 

 each side the neck, commencing at a small distance 

 beyond the eyes, is a row of seven pretty large, 

 equidistant, round spiracles or breathing-holes, each 

 leading to a deep sacculus lying in an oblique di- 

 rection towards the head : these seven sacculi on 

 each side are lined with a red pleated membrane, 

 and have no communication with each other, but 

 pass by their respective double ducts to the inside 

 of the mouth : towards the lower part of the back 

 commences the first dorsal fm, which is rather 

 shallow, with a rounded outline: the second, whicl> 



