SEA LAMPREY. 
393 
pointed in front; but when the mouth is open the appearance 
is as if the head had been cut off; aperture on the top of the 
head a little in front of the line of the eyes, and with a raised 
rim; the eye moderate, lively, proportionally larger in the 
smaller examples. In a line with the eye are seven branchial 
openings, lowering gradually in the order in which they are 
arranged. The first dorsal fin behind the middle of the body, 
shorter than the second, from which it is widely separated; the 
second running to the root of the tail, but not joined to it. 
In this example the tail is square, but in others pointed. The 
vent opposite the beginning of the second dorsal fin. The 
colour is varied, mottled with blue and green, but when taken 
in the sea, much more dull, and often of a uniform bluish tint; 
whitish below; the eye pink, red, or silvery. 
The arrangement and structure of the teeth are characteristic 
of the species of this family, and therefore require a distinct 
description; as do a few other particulars of the structure of this 
fish, and especially of the organization of its head. When the 
month is expanded it forms a wide oval, of which the border 
is fleshy and apparently sensitive. In front of the gullet is a 
curved row of stout teeth, each of which has a stout firm base, 
with a sharp point; and a little behind them, on the floor, first 
a pair of elevated rasp-like teeth, having on their upper edge 
a row of very sharp points. Close behind these a pair ot 
elliptic shape, with their narrow convex bend foremost; and 
along their edge a row of sharp points. On the upper portion 
of the mouth or palate, on the fauces two teeth, close together, 
each with a broad and firm base and short, sharp point. In a 
line above them upward three similar teeth, each smaller than 
the next below it; and four rows of similar teeth pass from 
these in regular succession, in an arched manner, to the border 
of the mouth; each row containing five or six, except the 
highest, where there are only one or two of small size. In 
front of the lower portion of the mouth are three or four 
regular rows of teeth in a circular course; and thus the whole 
surface of the mouth and throat is covered with regularly 
arranged strong teeth, which are not solid, but mere shells 
that are shed by being thrust off and renewed by others 
that rise within themselves. The throat teeth are moved by 
muscles appropriated to themselves, and the seven of the rovV 
VOL. IV. iJ E 
