AND EXPLANATION OF TERMS. 
5 
perpendicular muscular partitions {septa), all of which are 
inserted into the column-wall, hut advance into the cavity 
in various degrees. Some are inserted by their inner edge 
into the stomach-wall, completely dividing-ofF the cavity : 
these may be called primary septa {septa primordialia) . 
Others are placed intermediately between these, which do 
not reach the stomach-wall ; these are secondary septa 
{s. secundaria). Others, again, are intermediate between 
these and the former, whose height is still lower (these may 
be distinguished as tertiary (s. tertiaria) ; and so on, if 
tliere be any series beyond this. The spaces thus parted 
off in the cavity, I would call intersepts {intersepta). 
The free edges of the secondary and tertiary septa, and also 
of the primary ones below the stomach, carry a thin 
membrane which encloses the ovaries {ovaria), and is 
terminated by a sort of CORD {craspedum), much twisted 
and involved. Long missile cords {acontia) are in some 
species attached by one end to the partitions, and lie coiled- 
up, or float freely, in the intersepts : these are, by the volun- 
tary contractions of the animal, forcibly ejected through the 
loop-holes, into which they are then gradually withdrawn. 
Both the craspeda and the acontia are almost wholly com- 
posed of THREAD-CAPSULES {cnidce), which contain a coiled 
WIRE {ecthormim). This wire is shot out under particular 
stimulus, and is an efficient weapon of offence ; it is usually 
surrounded with one or more spiral bands composing the 
SCREW {strehla), each of which carries a series of barbs 
{pterygia) ; and the whole apparatus is a vehicle for the 
infusion of some highly venomous fluid. 
The different conditions assumed by the animal, may be 
distinguished as the FLOWER {anthus), Avhen the disk with 
its tentacles is expanded; the button {oncus), when these 
are retracted and concealed by the closing over them of the 
summit of the column. 
