418 
T,ANCT!T,ET. 
would remain motionless, lying flat on its side with its mouth 
open, and ^ to all appearance dead, for thirty or forty minutes, 
or longer if not disturbed. Two days after its capture he put 
a quantity of shell-sand in the vessel, which alarmed it, and 
for a few seconds it swam with increased velocity, and then 
suddenly disappeared in the bed of sand at the bottom of the 
glass. In fifty minutes from this time a third part of its body 
appeared above the sand in an upright position, and quite still, 
with the mouth open, and the filaments slightly bent at their 
extremities; but on agitating the water with a piece of straw 
the body was partly drawn in; and on repeating the annoyance 
it disappeared^ altogether. Mr. Cocks adds that he carefully 
watched this little creature, with the assistance of a pocket-leus, 
at every hour in the day for eight days, without having had 
an opportunity of seeing more of it above the sand than the 
open mouth and reflected filaments; as if patiently waiting for 
its prey. 
The largest example of this fish which I have seen was in 
length two inches and three tenths, with a depth of three 
tenths of an inch, exclusive of the fins; the body sharp at tie 
tail, but less so at the head, as the generic name might lead 
us to suppose; the body and head so transparent that the 
inward structure can be discerned; and what renders this little 
creature highly curious is the fact, that with a vertebral colun n 
or backbone distinctly made out with its separate joints, there 
is no separate skull, so what little appearance of brain there 
is can only be compared to what is found in creatures that 
have no vertebrce; and especially to that very inferior class of 
ringed animals which bear the name of Entozoa. The jointed 
vertebrae in the Lancelet are continued forward on the head, 
even to the point of the snout. The mouth is large and under 
the head; where it does not lie across, as in other fishes, but 
lengthwise; and when at rest its inward cavity contains the 
lengthened filaments, of which ten were counted, but there may 
be a couple more. They lie crossing each other within the 
mouth except when in action; and when dead they usually 
hang loosely outward. The number of lines which may be 
judged to mark the number of joints in the backbone was 
sixty; and between each of them and the next were five per- 
pendicular rays of a fin, with two or three anterior to the first 
